Supplements without the myths

Sleep & calmWeak evidence

5-HTP

5-hydroxytryptophan

5-HTP is an intermediate in making serotonin and melatonin from tryptophan, sourced from the seeds of Griffonia simplicifolia. It may affect mood and sleep, but carries a risk of drug interactions.

Forms & use DigestionWeak evidence

Acacia fibre

gum arabic, acacia gum

Acacia fibre is a soluble fibre from acacia tree sap that ferments slowly in the gut and feeds beneficial bacteria. Thanks to slow fermentation it causes less wind than many other prebiotics.

Forms & use Amino acidsWeak evidence

Acetyl-L-carnitine

ALCAR

An acetylated form of carnitine that crosses into the brain more easily. Besides fatty acid transport, it provides acetyl groups for making the neurotransmitter acetylcholine.

Forms & use DigestionModerate evidence

Activated charcoal

medicinal charcoal, activated carbon

Activated charcoal is a highly porous carbon (e.g. from coconut shells) that binds gases and many substances in the digestive tract onto its surface. EFSA has approved a claim for reducing excessive flatulence after eating.

Forms & use Adaptogens & herbsWeak evidence

Adaptogen complex

adaptogen blend

An adaptogen complex combines several herbs, typically ashwagandha, rhodiola, ginseng, eleuthero, maca or mushrooms such as reishi. Individual doses are often low, so quality depends on the label.

Forms & use LongevityWeak evidence

Agaricus blazei

almond mushroom, Agaricus subrufescens

Agaricus blazei (almond mushroom) is an edible mushroom from Brazil that is rich in beta-glucans. It is studied mainly for immune support, but human evidence is limited.

Forms & use OtherNo evidence

Alfalfa

lucerne, Medicago sativa

Alfalfa is a legume whose leaves contain vitamin K, minerals, saponins and phytoestrogens. It is sold as a nutrient source, but evidence of health benefits is lacking.

Forms & use Omega-3 & fatsWeak evidence

Alkylglycerols

shark liver oil, ratfish liver oil

Alkylglycerols are lipids found abundantly in shark and ratfish (chimaera) liver oil, and in small amounts in breast milk. They are sold for immune support, but human evidence is limited.

Forms & use Amino acidsWeak evidence

Almond protein

almond protein powder

Almond protein is finely ground defatted almond flour with a protein content usually around 40–50%. It also provides fibre, vitamin E and magnesium and has a pleasant taste.

Forms & use DigestionWeak evidence

Aloe vera

Aloe barbadensis

Aloe vera is a succulent whose leaves yield an inner gel and a bitter yellow latex containing laxative anthraquinones. The gel is used for skin and digestion, while the latex is restricted in EU foods because of safety concerns.

Forms & use LongevityModerate evidence

Alpha-lipoic acid

ALA, thioctic acid, R-lipoic acid

Alpha-lipoic acid is a compound the body makes in small amounts that takes part in energy production in the mitochondria. It acts as an antioxidant and is studied mainly for diabetic neuropathy and insulin sensitivity.

Forms & use Amino acidsWeak evidence

Amino acid complex

amino acids, EAA tablets

Amino acid complexes contain a mix of amino acids, often from hydrolysed whey or beef collagen. The composition and essential amino acid content vary widely, so quality depends on the label.

Forms & use PerformanceModerate evidence

Amylopectin

highly branched starch, waxy maize

Amylopectin is the branched part of starch; in sports products it is a specially processed high-molecular-weight starch (e.g. from waxy maize or barley). It has low osmolality, so some people tolerate it better in the stomach during exercise.

Forms & use OtherWeak evidence

Andrographis

Andrographis paniculata, green chiretta

Andrographis is a bitter herb from traditional Asian medicine whose active compound is andrographolide. It is mainly used to ease cold symptoms.

Forms & use Sleep & calmWeak evidence

Apigenin

chamomile extract

Apigenin is a flavonoid from chamomile, parsley and celery that binds to calming receptors in the brain. Direct human studies with pure apigenin are very few.

Forms & use DigestionModerate evidence

Apple fibre

apple pectin, apple pomace fibre

Apple fibre is made from dried apple pomace and contains soluble pectin as well as insoluble fibre. In the gut pectin forms a gel that slows sugar absorption and binds bile acids.

Forms & use OtherWeak evidence

Aronia

black chokeberry, Aronia melanocarpa

Aronia is a small dark berry with a strongly astringent taste and a very high content of anthocyanins and proanthocyanidins. Smaller studies look at its effects on blood pressure, blood lipids and blood sugar.

Forms & use DigestionWeak evidence

Artichoke

globe artichoke, artichoke leaf extract, Cynara scolymus

Artichoke leaf extract contains bitter compounds and substances such as cynarin that stimulate bile production and flow. The European Medicines Agency recognises its traditional use for digestive complaints.

Forms & use Adaptogens & herbsModerate evidence

Ashwagandha

withania, Indian ginseng

Ashwagandha (Withania somnifera) is an Ayurvedic adaptogen whose root is used to cope with stress. It is one of the best-studied adaptogens, though most studies are short-term.

Forms & use LongevityWeak evidence

Astaxanthin

Haematococcus pluvialis, algae carotenoid

Astaxanthin is a red carotenoid from the microalga Haematococcus pluvialis that gives salmon and shrimp their colour. It is a strong antioxidant in the laboratory, but evidence of benefits in humans is still limited.

Forms & use Adaptogens & herbsWeak evidence

Astragalus

Astragalus membranaceus, huang qi, milkvetch

Astragalus is a herb of traditional Chinese medicine whose root contains polysaccharides, saponins (astragalosides) and flavonoids. It is used mainly for immune support and fatigue.

Forms & use VitaminsModerate evidence

B complex

B vitamin complex

A B complex contains all or most B vitamins (B1, B2, B3, B5, B6, biotin, folate, B12) in one tablet. It suits restricted or plant-based diets and periods of higher demand, but quality depends heavily on the forms and doses on the label.

Forms & use Adaptogens & herbsModerate evidence

Bacopa

Bacopa monnieri, brahmi

Bacopa monnieri is an Ayurvedic herb whose extracts contain bacosides. It is one of the best-studied herbal nootropics, but its effect builds slowly, usually over 8–12 weeks.

Forms & use OtherWeak evidence

Barley grass

young barley, green barley

Barley grass is the dried young shoots of barley harvested before the grain forms, sold as powder, juice powder or tablets. It contains chlorophyll, fibre, some vitamins and polyphenols, but the amount per serving is small.

Forms & use Amino acidsWeak evidence

BCAA

branched-chain amino acids (leucine, isoleucine, valine)

BCAAs are three essential amino acids – leucine, isoleucine and valine – of which leucine triggers muscle protein synthesis. With enough protein from food or protein powder, however, standalone BCAAs add little or no extra benefit.

Forms & use OtherWeak evidence

Bee pollen

flower pollen

Bee pollen consists of flower-pollen granules collected by bees, containing carbohydrates, protein, vitamins and polyphenols. Composition depends on plants and region, and human evidence for health effects is limited.

Forms & use OtherWeak evidence

Beef organs (desiccated)

liver, heart, kidney, testicle capsules, organ complex

These are freeze-dried beef organs in capsules, most often liver but also heart, kidney, spleen or testicles. Liver is naturally rich in vitamin A, B12, iron and copper, but the benefit of capsules over a normal diet is not proven.

Forms & use Amino acidsModerate evidence

Beef protein

beef protein isolate

Beef protein is made from beef meat or connective tissue by hydrolysis and protein isolation, and it is lactose-free. It is often rich in collagen, so it has less leucine than whey unless fortified.

Forms & use OtherModerate evidence

Berberine

berberine HCl, barberry (Berberis), goldenseal

Berberine is a yellow plant alkaloid from barberry and other plants, used in traditional Chinese and Ayurvedic medicine. It affects sugar and fat metabolism and is therefore studied for raised blood glucose and cholesterol.

Forms & use PerformanceStrong evidence

Beta-alanine

β-alanine

Beta-alanine is an amino acid muscles use to make carnosine, which buffers acid build-up during intense exercise. The effect appears only after several weeks of regular use.

Forms & use VitaminsWeak evidence

Beta-carotene

provitamin A

Beta-carotene is an orange plant pigment that the body converts to vitamin A as needed. Unlike retinol it does not cause vitamin A toxicity, but in smokers high-dose supplements increased lung cancer risk.

Forms & use OtherStrong evidence

Beta-glucans

oat beta-glucan, beta-glucan

Beta-glucans are soluble fibres from oats, barley, yeast and mushrooms. Oat and barley beta-glucans have an EU-approved health claim for lowering LDL cholesterol at an intake of 3 g per day.

Forms & use OtherModerate evidence

Beta-sitosterol

plant sterol, phytosterol

Beta-sitosterol is the most common plant sterol, found in nuts, seeds and vegetable oils. It is used for urinary symptoms with an enlarged prostate and as part of sterols that lower LDL cholesterol.

Forms & use DigestionWeak evidence

Betaine HCl

betaine hydrochloride, betaine with pepsin

Betaine HCl is a compound that releases hydrochloric acid in the stomach and temporarily acidifies its contents. It is used when low stomach acid is suspected, often together with pepsin or bitter herbs.

Forms & use PerformanceWeak evidence

BHB ketones

beta-hydroxybutyrate, exogenous ketones, keto booster

BHB (beta-hydroxybutyrate) is a ketone body the body makes naturally during fasting or a ketogenic diet, which the brain and muscles can use as fuel. Supplements temporarily raise blood ketones, but they do not burn fat on their own.

Forms & use VitaminsWeak evidence

Biotin

vitamin B7, vitamin H

Biotin is a B vitamin involved in fat, carbohydrate and protein metabolism and in maintaining healthy hair and skin. True deficiency is rare, and in people without it a supplement does not visibly improve hair or nails.

Forms & use OtherWeak evidence

Bitter melon

bitter gourd, Momordica charantia

Bitter melon is a tropical vegetable used in traditional medicine to support blood sugar levels. It contains compounds such as charantin and polypeptide-p, but human study results are mixed and the effect is rather small.

Forms & use OtherWeak evidence

Black cohosh

Actaea racemosa, Cimicifuga racemosa

Black cohosh is a North American herb whose root is used to ease menopausal symptoms. It does not contain phytoestrogens in the classic sense and its exact mechanism is unknown.

Forms & use Omega-3 & fatsWeak evidence

Blackcurrant seed oil

blackcurrant oil, GLA

Blackcurrant seed oil provides the omega-6 gamma-linolenic acid (GLA), the omega-3 alpha-linolenic acid (ALA) and stearidonic acid (SDA). It is used for skin and as mild anti-inflammatory support.

Forms & use OtherWeak evidence

Blood sugar support blend

glycaemic herbal complex, sugar balance blend

Herbal blood sugar blends typically combine berberine, cinnamon, gymnema, bitter melon, fenugreek, white mulberry or alpha-lipoic acid, often with chromium and zinc. Their effect and quality depend on the composition and doses on the label; the blends themselves are poorly studied.

Forms & use MineralsModerate evidence

Bone support blend

bone complex, calcium + magnesium + D + K

Bone complexes usually combine calcium, magnesium, vitamin D3, vitamin K2 and sometimes zinc, boron or manganese. The benefit depends on the doses of each ingredient on the label and on how much calcium and vitamin D you already get from food and sunlight.

Forms & use Omega-3 & fatsWeak evidence

Borage oil

starflower oil, GLA

Borage oil is pressed from the seeds of borage (starflower) and is the richest common source of gamma-linolenic acid (GLA), an omega-6 fatty acid. It is used mainly for dry skin, eczema and joints.

Forms & use MineralsWeak evidence

Boron

B

Boron is a trace element that probably influences the metabolism of calcium, magnesium, vitamin D and sex hormones. It is not recognised as an essential nutrient and evidence for supplements is still limited.

Forms & use OtherWeak evidence

Boswellia

Indian frankincense, Boswellia serrata

Boswellia is the resin of the Boswellia serrata tree, which contains boswellic acids with anti-inflammatory properties. It is mainly used for joint support.

Forms & use VitaminsWeak evidence

Brewer's yeast

Saccharomyces cerevisiae, inactive yeast

Brewer's yeast is inactivated Saccharomyces cerevisiae yeast that provides B vitamins, protein, chromium and selenium. It is traditionally used for hair, nails and skin, but evidence for these effects is weak.

Forms & use DigestionWeak evidence

Bromelain

pineapple enzyme

Bromelain is a mixture of protein-digesting enzymes obtained from pineapple stems. With food it aids digestion; on an empty stomach it is used for its possible anti-inflammatory and anti-swelling effect.

Forms & use OtherWeak evidence

Burdock (root)

Arctium lappa

Burdock root is a traditional herb and, in Asia, a vegetable rich in inulin and polyphenols. It is used in folk medicine for 'blood cleansing' and problem skin, but good human studies are very limited.

Forms & use OtherModerate evidence

Butcher's broom

Ruscus aculeatus

Butcher's broom root contains ruscogenins, which tighten vein walls and reduce their permeability. It is used for chronic venous insufficiency, heavy legs and haemorrhoids.

Forms & use OtherWeak evidence

Butterbur

Petasites hybridus

Butterbur is a herb whose root extract has been studied mainly for migraine prevention and hay fever. The raw plant contains pyrrolizidine alkaloids that damage the liver, so only extracts with these compounds removed should be used.

Forms & use DigestionWeak evidence

Butyrate

butyric acid, sodium / calcium-magnesium butyrate, tributyrin

Butyrate is a short-chain fatty acid normally produced by gut bacteria from fibre, and the main energy source for colon cells. As a supplement it is studied for irritable bowel and inflammatory bowel disease.

Forms & use OtherModerate evidence

Cacao

cocoa, cocoa flavanols, Theobroma cacao

Cacao comes from the seeds of the cacao tree and is rich in flavanols (epicatechin), magnesium and iron, and also contains theobromine and a little caffeine. In supplements it is often blended with functional mushrooms, collagen or maca.

Forms & use PerformanceStrong evidence

Caffeine

caffeine anhydrous, guarana

Caffeine is a stimulant found naturally in coffee, tea and guarana that blocks adenosine receptors and reduces the feeling of tiredness. It is one of the best-studied performance aids.

Forms & use MineralsModerate evidence

Calcium

Ca

Calcium is the most abundant mineral in the body and the foundation of bones and teeth; it is also involved in muscle contraction and blood clotting. A supplement makes sense mainly when you do not get enough from food (dairy, mineral water, vegetables, legumes).

Forms & use OtherNo evidence

Calcium D-glucarate

glucaric acid calcium salt

Calcium D-glucarate is the calcium salt of glucaric acid, which occurs in small amounts in fruit and vegetables (e.g. apples, broccoli, citrus). It is marketed for liver "detox" and oestrogen metabolism, but human evidence is lacking.

Forms & use VitaminsWeak evidence

Camu camu

Myrciaria dubia

Camu camu is a sour Amazonian fruit and one of the richest natural sources of vitamin C. As a powder it serves mainly as a food source of vitamin C and polyphenols.

Forms & use DigestionWeak evidence

Caprylic acid

octanoic acid, C8

Caprylic acid is a medium-chain fatty acid found in coconut and palm kernel oil. It acts against yeasts in the lab, but proven effects in humans are few.

Forms & use DigestionWeak evidence

Carob

carob powder, locust bean, Ceratonia siliqua

Carob is a powder made from ground carob pods with a naturally sweet taste, used as a cocoa substitute without caffeine or theobromine. It contains fibre and polyphenols; health benefits are only weakly supported.

Forms & use Amino acidsStrong evidence

Casein

micellar casein, milk protein

Casein makes up about 80% of cow's milk protein and forms a gel in the stomach, so it digests slowly and releases amino acids over several hours. It suits situations where you want a longer protein supply, such as before sleep.

Forms & use OtherWeak evidence

Cat's claw

Uncaria tomentosa, uña de gato

Cat's claw is an Amazonian vine whose bark is traditionally used for inflammation and immune support. Human evidence comes from a few small studies.

Forms & use Sleep & calmWeak evidence

CBD

cannabidiol, CBD oil

CBD (cannabidiol) is a non-psychoactive compound from hemp, sold mainly as an oil in various strengths (e.g. 5, 10 or 15%). Prescription CBD has evidence in some rare forms of epilepsy, but for everyday supplements for stress and sleep the evidence is weak.

Forms & use OtherWeak evidence

Celery seed

Apium graveolens seed

Celery seed contains an essential oil and compounds such as 3-n-butylphthalide and apigenin. It is traditionally used as a diuretic and for gout and joint complaints, but human studies are almost absent.

Forms & use OtherWeak evidence

Ceramides (phytoceramides)

phytoceramides, glucosylceramides

Ceramides are lipids that make up a large part of the skin's protective barrier. Supplements use plant phytoceramides (most often from wheat, rice or konjac) intended to support skin hydration from within.

Forms & use Adaptogens & herbsNo evidence

Chaga

Inonotus obliquus

Chaga is a fungus growing mainly on birch trees that contains polyphenols, betulin and polysaccharides. It is promoted as an antioxidant and for immunity, but clinical studies in humans are almost absent.

Forms & use Sleep & calmWeak evidence

Chamomile

German chamomile, Matricaria chamomilla

Chamomile is one of the most widely used medicinal herbs; it contains the flavonoid apigenin and essential oils (bisabolol, chamazulene). It is traditionally used for calm, sleep and digestive complaints.

Forms & use Amino acidsWeak evidence

Chia protein

chia seed protein

Chia protein is defatted chia seed flour with a protein content usually around 40–55% and a large share of fibre. Part of the omega-3 (ALA) is removed during defatting.

Forms & use OtherWeak evidence

Chinese skullcap

Baikal skullcap, Scutellaria baicalensis, baicalin

Chinese skullcap is a traditional Chinese medicine herb whose root contains the flavonoids baicalin, baicalein and wogonin. Its anti-inflammatory and calming effects are being studied, but human evidence is weak.

Forms & use OtherModerate evidence

Chitosan

chitosan fibre

Chitosan is a fibre obtained mostly from crustacean shells (or from fungi) that binds part of dietary fat in the gut. EFSA approved a claim that chitosan contributes to the maintenance of normal blood cholesterol at an intake of 3 g per day; its effect on weight loss is small.

Forms & use OtherWeak evidence

Chlorella

Chlorella vulgaris, Chlorella pyrenoidosa, green algae

Chlorella is a single-celled green alga rich in protein, chlorophyll, iron and vitamin K. It is sold as a "detox" and superfood, but good evidence of benefits in humans is limited.

Forms & use OtherNo evidence

Chlorophyll

chlorophyllin, plant green pigment

Chlorophyll is the green pigment of plants; supplements most often use water-soluble sodium copper chlorophyllin. Its popularity comes largely from social media, and good evidence for health effects is lacking.

Forms & use OtherWeak evidence

Cholesterol support blend

cholesterol complex, cardio complex

Cholesterol blends typically combine plant sterols, artichoke, bergamot, garlic, policosanol, beta-glucans, coenzyme Q10 and sometimes red yeast rice. Their effect and quality depend on the composition and doses on the label.

Forms & use VitaminsModerate evidence

Choline

CDP-choline, citicoline

Choline is a vitamin-like nutrient needed for acetylcholine, cell membranes and liver function. It is found mainly in eggs, liver and meat.

Forms & use OtherWeak evidence

Chondroitin

chondroitin sulfate

Chondroitin sulfate is a natural part of cartilage that helps it retain water and withstand pressure; in supplements it comes from animal or fish cartilage. It is used for osteoarthritis, alone or with glucosamine.

Forms & use MineralsWeak evidence

Chromium

Cr

Chromium is a trace element involved in macronutrient metabolism and the maintenance of normal blood sugar. True deficiency is rare and the benefit of supplements in healthy people is small.

Forms & use OtherWeak evidence

Cinnamon

Ceylon cinnamon, cassia, Cinnamomum verum

Cinnamon is a spice made from the dried bark of Cinnamomum trees. It is studied for blood sugar, but results are mixed and the effect is rather small; the key difference is between Ceylon cinnamon and cassia, which contains a lot of coumarin.

Forms & use OtherWeak evidence

CLA

conjugated linoleic acid

CLA is a group of linoleic acid isomers found naturally in dairy and ruminant meat. It is marketed for fat loss, but the effect is small.

Forms & use Omega-3 & fatsModerate evidence

Cod liver oil

cod oil

A traditional oil from cod liver that naturally contains vitamins A and D alongside EPA and DHA. The vitamin A content is why total intake must be watched.

Forms & use LongevityModerate evidence

Coenzyme Q10

CoQ10, ubiquinone, ubiquinol

Coenzyme Q10 is a compound the body makes itself; it is essential for energy production in the mitochondria and acts as an antioxidant. Its levels decline with age and with statin use.

Forms & use Amino acidsModerate evidence

Collagen

collagen peptides, hydrolysed collagen, UC-II

Collagen is the main structural protein of skin, tendons, cartilage and bone. Hydrolysed collagen peptides are absorbed as short peptides and amino acids, while undenatured type II collagen (UC-II) works at a small dose through the gut immune system.

Forms & use DigestionWeak evidence

Colostrum

bovine colostrum, first milk

Colostrum is the first milk cows produce after calving, rich in antibodies (immunoglobulins), lactoferrin and growth factors. It is used to support immunity and the gut barrier, especially in athletes.

Forms & use MineralsWeak evidence

Copper

Cu

Copper is a trace element needed for iron transport, collagen formation, hair and skin pigmentation and normal immune and nervous system function. A supplement is mainly worthwhile with long-term higher-dose zinc, which can cause copper deficiency.

Forms & use Adaptogens & herbsWeak evidence

Cordyceps

Cordyceps militaris, Cordyceps sinensis

Cordyceps is a mushroom from traditional Asian medicine containing cordycepin, adenosine and polysaccharides. It is used to support energy and endurance, with inconsistent study results.

Forms & use OtherModerate evidence

Cranberry

American cranberry, Vaccinium macrocarpon

Cranberry contains A-type proanthocyanidins that may make it harder for certain bacteria to stick to the urinary tract wall. It is mainly used to help prevent recurrent urinary tract infections.

Forms & use PerformanceStrong evidence

Creatine

creatine monohydrate

Creatine is a natural muscle compound that helps rapidly regenerate energy (ATP) during short, intense efforts. It is one of the best-researched sports supplements.

Forms & use PerformanceWeak evidence

D-aspartic acid

DAA, D-aspartate

D-aspartic acid is an amino acid involved in hormonal signalling in the body. It is sold to support testosterone, but study results are inconsistent.

Forms & use OtherWeak evidence

D-mannose

mannose

D-mannose is a simple sugar that is largely excreted in urine, where it may bind to certain bacteria and help flush them out of the urinary tract. It is used as a supplement to help prevent recurrent urinary tract infections.

Forms & use PerformanceWeak evidence

Damiana

Turnera diffusa

Damiana is a Mexican shrub whose leaves are traditionally used as an aphrodisiac and a mild relaxant. Good human studies are almost absent; most evidence is traditional or from animals.

Forms & use DigestionWeak evidence

Dandelion

Taraxacum officinale

Dandelion is a common herb whose root is traditionally used to support digestion and bile flow, and whose leaf is used as a mild diuretic. Clinical evidence in humans is limited.

Forms & use OtherWeak evidence

Devil's claw

Harpagophytum procumbens

Devil's claw is a southern African plant whose root contains harpagoside and other iridoid glycosides. It is used for back and joint pain, where it may bring a modest improvement.

Forms & use PerformanceStrong evidence

Dextrose

glucose, grape sugar

Dextrose is pure glucose, a simple sugar absorbed very quickly that raises blood sugar fast. In sport it is used for a quick top-up of energy and glycogen.

Forms & use DigestionModerate evidence

Digestive enzymes

enzymes, lactase, enzyme blend

Digestive enzymes help break down proteins, fats, carbohydrates and certain sugars in food. The best-proven is lactase for lactose intolerance; evidence for other blends is weaker.

Forms & use Amino acidsNo evidence

Dimethylglycine

DMG, N,N-dimethylglycine

Dimethylglycine (DMG) is a derivative of the amino acid glycine that forms in the body when betaine is converted to methionine. It is sold for endurance, immunity and as a "methyl donor", but good human evidence is lacking.

Forms & use LongevityNo evidence

DNA protection blend

antioxidant complex, 'DNA protect'

DNA protection blends usually combine antioxidants and nutrients involved in DNA repair – e.g. vitamins C and E, selenium, zinc, folate and B12, grape or green tea extracts, curcumin or NAD+ precursors. The quality and value of such a product depend on the composition and doses on the label; direct evidence that they protect DNA in humans is lacking.

Forms & use OtherNo evidence

Dong quai

Angelica sinensis, female ginseng

Dong quai is a root used in traditional Chinese medicine as a "women's herb" for menstrual and menopausal complaints. However, good-quality studies have not confirmed an effect of the herb on its own.

Forms & use Amino acidsModerate evidence

EAA – essential amino acids

9 essential amino acids

A mix of the nine amino acids the body cannot make and must get from food. Unlike BCAAs, it supplies all the building blocks needed for muscle protein synthesis.

Forms & use OtherWeak evidence

Echinacea

purple coneflower, Echinacea purpurea

Echinacea is a herb from the daisy family traditionally used to support immunity during colds. Study results are inconsistent and the effect is small at best.

Forms & use Amino acidsStrong evidence

Egg protein

egg white protein, albumin

Egg protein is dried egg white with high biological value and a complete set of essential amino acids. It is lactose-free and digests at a medium rate.

Forms & use OtherWeak evidence

Elderberry

black elder, Sambucus nigra

Black elder berries contain anthocyanins and other polyphenols with antioxidant properties. The extract is mainly used for colds and flu.

Forms & use MineralsModerate evidence

Electrolytes

hydration minerals, isotonic drink

Electrolytes are minerals – mainly sodium, potassium, magnesium and chloride – that keep fluid balance and allow nerves and muscles to work. Topping up makes sense during longer exercise, in heat, with heavy sweating or with diarrhoea.

Forms & use Adaptogens & herbsWeak evidence

Eleuthero

Siberian ginseng, Eleutherococcus senticosus

Eleuthero is a shrub from Siberia and north-east Asia that, despite its name, is not a true ginseng. It is traditionally used for fatigue and to build resilience.

Forms & use LongevityWeak evidence

Ergothioneine

L-ergothioneine, mushroom antioxidant

Ergothioneine is an amino-acid antioxidant made by fungi and some bacteria that the human body cannot produce. The body nevertheless absorbs it actively via its own transporter and stores it in tissues, which has led to hypotheses about a protective role.

Forms & use Omega-3 & fatsWeak evidence

Evening primrose oil

EPO

Oil from evening primrose seeds containing the omega-6 gamma-linolenic acid (GLA). It is traditionally used for skin issues and PMS, but scientific evidence is weak.

Forms & use Amino acidsWeak evidence

Faba bean protein

fava protein, broad bean protein

Faba bean protein is made from broad (fava) bean seeds and contains about 60–90% protein depending on processing. Its amino-acid profile is similar to pea – rich in lysine, lower in methionine.

Forms & use PerformanceNo evidence

Fadogia agrestis

Nigerian shrub

Fadogia agrestis is an African shrub whose stem is traditionally used as an aphrodisiac. It is sold as a testosterone booster, but the data come almost entirely from rat studies.

Forms & use DigestionWeak evidence

Fennel

fennel seed, Foeniculum vulgare

Fennel is a medicinal and culinary plant whose fruits contain an essential oil rich in anethole. It is traditionally used for bloating, wind and digestive discomfort.

Forms & use OtherWeak evidence

Fenugreek

Trigonella foenum-graecum

Fenugreek is a legume whose seeds are rich in soluble fibre (galactomannan) and saponins. It is studied for blood sugar, libido and testosterone in men, and traditionally used for milk supply in breastfeeding women.

Forms & use OtherWeak evidence

Feverfew

Tanacetum parthenium

Feverfew is a daisy-family herb whose leaves contain parthenolide. It is used mainly to prevent migraine, not to treat an attack already in progress.

Forms & use Omega-3 & fatsWeak evidence

Flaxseed oil

linseed oil

A plant oil rich in the omega-3 alpha-linolenic acid (ALA). The body converts ALA to EPA and DHA only to a small extent, so it is not a full substitute for fish oil.

Forms & use Adaptogens & herbsNo evidence

Fo-ti

Polygonum multiflorum, he shou wu

Fo-ti is the root of Polygonum multiflorum, used in traditional Chinese medicine for "rejuvenation" and against greying hair. Reliable evidence is lacking and there are repeated reports of liver injury.

Forms & use VitaminsStrong evidence

Folate

folic acid, vitamin B9, 5-MTHF

Folate (vitamin B9) is needed for cell division, DNA and blood formation and for converting homocysteine. Women planning a pregnancy are advised to take folic acid before conception to prevent neural tube defects in the baby.

Forms & use OtherWeak evidence

Fucoidan

brown seaweed polysaccharide

Fucoidan is a sulphated polysaccharide from brown seaweeds such as wakame, mozuku or kelp. Its effects on immunity and inflammation are studied in the lab and in animals, but human evidence is very limited.

Forms & use OtherNo evidence

Fulvic acid

fulvates, humic substances

Fulvic acid is a mixture of organic acids formed when plants break down in soil and peat; it is the main component of shilajit. It is sold for "better mineral absorption" and energy, but clinical evidence in humans is almost absent.

Forms & use Sleep & calmWeak evidence

GABA

gamma-aminobutyric acid

GABA is the brain's main calming neurotransmitter. Whether GABA from supplements reaches the brain is uncertain, and studies on its effects are small.

Forms & use PerformanceWeak evidence

Gamma-oryzanol

oryzanol, rice bran extract

Gamma-oryzanol is a mixture of ferulic acid esters and plant sterols extracted from rice bran and rice bran oil. It is marketed in sports nutrition for muscle and hormone support, but the evidence is weak.

Forms & use OtherWeak evidence

Garcinia cambogia

Malabar tamarind, HCA, hydroxycitric acid

Garcinia cambogia is a tropical fruit whose rind contains hydroxycitric acid (HCA). It is promoted to curb appetite and aid weight loss, but results from good-quality studies are disappointing.

Forms & use OtherModerate evidence

Garlic

Allium sativum, allicin, garlic extract

Garlic contains sulphur compounds that form allicin when crushed. Garlic supplements may modestly lower blood pressure and cholesterol; the effect on colds is less well supported.

Forms & use OtherWeak evidence

Garlic oil

garlic, garlic extract

Garlic oil contains sulphur compounds formed when garlic is processed. It is used mainly to support the heart, blood vessels and immunity.

Forms & use Amino acidsWeak evidence

Gelatin

beef gelatin, cooked collagen

Gelatin is partly broken-down collagen from animal skin and bones that sets when cooled in water. It is rich in glycine, proline and hydroxyproline but lacks tryptophan, so it is not a complete protein.

Forms & use DigestionWeak evidence

Gentian

gentian root, Gentiana lutea

Yellow gentian is one of the bitterest medicinal plants; its root contains bitter compounds that reflexively stimulate saliva, stomach juices and bile. It is traditionally used for poor appetite and a feeling of fullness.

Forms & use DigestionModerate evidence

Ginger

Zingiber officinale, ginger extract

Ginger is the root of Zingiber officinale and contains gingerols and shogaols. Its best-studied effect is against nausea.

Forms & use OtherWeak evidence

Ginkgo biloba

maidenhair tree

Ginkgo biloba is an extract from the leaves of the maidenhair tree that contains flavonoids and terpene lactones. It is used to support circulation and cognition, but in healthy people the evidence is not convincing.

Forms & use Adaptogens & herbsWeak evidence

Ginseng

Panax ginseng, Korean ginseng

Panax ginseng is a traditional Asian herb whose root contains ginsenosides. It is used for fatigue and to support mental performance and immunity.

Forms & use DigestionModerate evidence

Glucomannan

konjac, konjac fibre, Amorphophallus konjac

Glucomannan is a soluble fibre from the konjac tuber that can bind large amounts of water and forms a bulky gel in the stomach. This promotes fullness and reduces cholesterol absorption.

Forms & use OtherWeak evidence

Glucosamine

glucosamine sulfate, glucosamine HCl

Glucosamine is an amino sugar the body uses to build cartilage and joint fluid; in supplements it is made from shellfish shells or by fermentation. It is used mainly for knee osteoarthritis, but study results are mixed.

Forms & use OtherWeak evidence

Glucose support complex

blood sugar support, glucose blend

Glucose support complexes combine several ingredients, typically chromium, cinnamon, gymnema, berberine, alpha-lipoic acid, magnesium or bitter melon. Quality and effectiveness depend on the specific ingredients and doses stated on the label.

Forms & use LongevityWeak evidence

Glutathione

GSH, reduced glutathione

Glutathione is the main intracellular antioxidant, made by the body from cysteine, glycine and glutamate. When taken by mouth, part of it is broken down in the gut, so its effect is uncertain.

Forms & use Amino acidsWeak evidence

Glycine

L-glycine

Glycine is the simplest amino acid, a building block of collagen and glutathione and a calming neurotransmitter. It tastes slightly sweet.

Forms & use Amino acidsModerate evidence

Goat protein

goat whey protein, goat milk protein

Goat protein is made from goat milk and contains whey and casein with a complete profile of essential amino acids. For muscle growth it works similarly to cow milk protein; some people subjectively find it easier to digest.

Forms & use OtherWeak evidence

Goji

wolfberry, Lycium barbarum

Goji are the dried berries of the wolfberry plant, containing polysaccharides, carotenoids (especially zeaxanthin) and fibre. They are used as a food; claims of strong health effects are not well supported.

Forms & use OtherWeak evidence

Goldenseal

Hydrastis canadensis

Goldenseal is a North American herb whose root contains the alkaloids berberine and hydrastine. It is often combined with echinacea for colds, but human benefit is not convincingly shown and the herb strongly affects how medicines are broken down.

Forms & use Adaptogens & herbsWeak evidence

Gotu kola

Centella asiatica, Indian pennywort

Gotu kola is a herb of traditional Ayurvedic and Chinese medicine that contains triterpenes such as asiaticoside. It is used for vein support, skin healing and memory.

Forms & use LongevityWeak evidence

Grape seed extract

OPC, proanthocyanidins

Grape seed extract is rich in proanthocyanidins (OPC), polyphenols with antioxidant activity. It is studied mainly for blood pressure and venous insufficiency, where it may have a modest effect.

Forms & use OtherNo evidence

Grapefruit seed extract

GSE

Grapefruit seed extract (GSE) is made from grapefruit seeds, pulp and peel and sold as a 'natural antibiotic'. Independent analyses, however, found that the antimicrobial effect of some commercial products came from added synthetic preservatives (e.g. benzethonium chloride); clinical evidence in humans is lacking.

Forms & use OtherWeak evidence

Green coffee extract

chlorogenic acid, unroasted coffee

Green coffee extract is made from unroasted coffee beans and contains a lot of chlorogenic acid and less caffeine than regular coffee. It is sold as a weight-loss supplement and to support sugar metabolism.

Forms & use OtherWeak evidence

Green tea extract

EGCG, catechins, Camellia sinensis

Green tea extract is a concentrate of catechins, mainly EGCG, often with naturally occurring caffeine. It is sold mainly to support fat burning and as an antioxidant.

Forms & use OtherWeak evidence

Greens blend (super greens)

greens powder, superfood blend

Greens blends combine powders of green plants and algae (e.g. spirulina, chlorella, barley grass, wheatgrass, spinach), often with fruit, probiotics, enzymes or vitamins. Composition varies widely, so quality and effect depend on the label.

Forms & use DigestionModerate evidence

Guar gum

guar, partially hydrolysed guar gum (PHGG)

Guar gum is a soluble fibre from guar beans that swells strongly in water. The partially hydrolysed form (PHGG) does not gel as much and is used as a gentle prebiotic.

Forms & use PerformanceModerate evidence

Guarana

Paullinia cupana, guarana powder

Guarana is a South American vine whose seeds contain more caffeine than coffee beans, along with theobromine and tannins. Its effect on alertness and performance mainly reflects its caffeine content.

Forms & use OtherWeak evidence

Hair, skin and nails complex

beauty complex, beauty gummies

Beauty complexes combine vitamins and minerals (biotin, zinc, selenium, copper, vitamins A, C, E and B vitamins), often with collagen, hyaluronic acid or plant extracts. They help mainly if you are short of one of the ingredients; quality depends on the label.

Forms & use OtherModerate evidence

Hawthorn

Crataegus

Hawthorn is a shrub whose leaves, flowers and berries contain flavonoids and oligomeric proanthocyanidins. It is traditionally used to support the heart; it has been studied most as an add-on to treatment in mild heart failure.

Forms & use Amino acidsWeak evidence

Hemp protein

hemp seed protein

Hemp protein is made from pressed industrial hemp seeds and provides protein, fibre and omega-3 and omega-6 fatty acids. Its protein content is lower (usually around 50%) and it contains no relevant amount of psychoactive THC.

Forms & use DigestionNo evidence

Herbal cleanse (blend)

detox blend, cleanse tea, colon cleanse

Herbal cleanse products are blends of herbs sold to "detox" the body, often containing laxative (senna, buckthorn, aloe) or diuretic ingredients. The body cleans itself through the liver and kidneys, and there is no evidence that these blends improve that process.

Forms & use OtherWeak evidence

Hibiscus

roselle, Hibiscus sabdariffa

Roselle hibiscus is a plant whose calyces are used for a tart red tea rich in anthocyanins. Smaller studies suggest a modest reduction in blood pressure.

Forms & use PerformanceWeak evidence

HMB

beta-hydroxy-beta-methylbutyrate

HMB is a metabolite of the amino acid leucine that the body makes in small amounts. As a supplement it is used to help preserve muscle mass and support recovery.

Forms & use Adaptogens & herbsWeak evidence

Holy basil

tulsi, Ocimum sanctum

Holy basil (tulsi) is an Ayurvedic herb used as an adaptogen for stress. Human studies are small and short-term.

Forms & use PerformanceWeak evidence

Horny goat weed (Epimedium)

epimedium, icariin

Epimedium is a traditional Chinese medicine herb whose main active compound is icariin. It is sold mainly for libido and erection support, but human evidence is limited.

Forms & use OtherWeak evidence

Hyaluronic acid

sodium hyaluronate, HA

Hyaluronic acid is a natural component of skin, cartilage and joint fluid that binds large amounts of water. As a supplement it is taken for skin hydration and joint support, although it is partly broken down during digestion.

Forms & use LongevityWeak evidence

Hydroxytyrosol

olive polyphenols, olive extract

Hydroxytyrosol is a polyphenol from olives and extra virgin olive oil and one of the most potent natural antioxidants known. EFSA has approved a claim for olive oil polyphenols on protecting LDL lipids from oxidation.

Forms & use OtherWeak evidence

Immune throat spray

throat spray, propolis spray

Immune throat sprays usually contain propolis, zinc, extracts of sage, echinacea, elderberry, thyme or Iceland moss, sometimes vitamin C and honey. Their effect and quality depend on the composition and concentration on the label; they act mainly locally in the throat.

Forms & use OtherWeak evidence

Indole-3-carbinol

I3C, broccoli extract

Indole-3-carbinol is formed from glucosinolates in cruciferous vegetables such as broccoli and cabbage and is converted in the stomach into DIM and other compounds. It is studied for its effect on estrogen metabolism in the liver.

Forms & use OtherModerate evidence

Inositol

myo-inositol, D-chiro-inositol

Inositol is a vitamin-like compound involved in insulin signalling and some neurotransmitters. It is studied most in polycystic ovary syndrome (PCOS).

Forms & use DigestionModerate evidence

Inulin

fructans, oligofructose, FOS, chicory inulin

Inulin is a soluble fibre from chicory root, agave or Jerusalem artichoke that the body cannot digest on its own. It feeds beneficial gut bacteria, especially bifidobacteria, and therefore acts as a prebiotic.

Forms & use MineralsStrong evidence

Iodine

iodide, I

Iodine is essential for making thyroid hormones, which regulate metabolism and the development of the foetal brain. Table salt is commonly iodised, so a supplement is mainly needed by pregnant and breastfeeding women or people who do not use salt and eat no fish or dairy.

Forms & use OtherNo evidence

Irish moss

Chondrus crispus, sea moss

Irish moss is a red seaweed from which carrageenan is obtained and which contains iodine and minerals. It is popular on social media as a "superfood", but clinical studies in humans are lacking.

Forms & use MineralsStrong evidence

Iron

Fe

Iron is part of haemoglobin, which carries oxygen in the blood, and it supports energy production and brain function. Deficiency is most common in menstruating women, in pregnancy, on plant-based diets and in endurance athletes.

Forms & use DigestionWeak evidence

Jerusalem artichoke

sunchoke, topinambur extract

Jerusalem artichoke is a tuber rich in inulin, a soluble prebiotic fibre. Inulin feeds beneficial gut bacteria, especially bifidobacteria.

Forms & use Adaptogens & herbsWeak evidence

Jiaogulan

Gynostemma pentaphyllum, five-leaf ginseng

Jiaogulan is an Asian climbing plant whose leaves contain saponins similar to ginsenosides. It is drunk as tea or taken as an extract, but human studies are small.

Forms & use OtherWeak evidence

Joint complex

joint support blend, joint formula

Joint complexes combine several ingredients, typically glucosamine, chondroitin, MSM, collagen or gelatine, hyaluronic acid, vitamin C and sometimes curcumin or boswellia. Quality depends on the specific ingredients and their doses on the label.

Forms & use OtherWeak evidence

Kidney herbal blend

kidney and urinary tract support, diuretic tea

These are blends of diuretic herbs, typically birch, goldenrod, horsetail, nettle, parsley root and sometimes bearberry or cranberry. Composition varies widely, so quality and suitability depend on the label.

Forms & use DigestionWeak evidence

Kombucha

tea fungus, kombucha starter (SCOBY)

Kombucha is a fermented sweetened tea made with a symbiotic culture of bacteria and yeasts (SCOBY). It contains organic acids, tea polyphenols and live microorganisms, but human studies are almost non-existent.

Forms & use Omega-3 & fatsModerate evidence

Krill oil

Antarctic krill oil

Oil from small marine crustaceans providing EPA and DHA bound mostly to phospholipids, plus the natural pigment astaxanthin. It usually delivers less omega-3 per dose than fish oil.

Forms & use PerformanceWeak evidence

L-arginine

arginine, arginine AKG

Arginine is an amino acid the body uses to make nitric oxide, which supports blood flow. Taken orally, much of it is broken down in the gut and liver, so citrulline is often more effective.

Forms & use Amino acidsWeak evidence

L-carnitine

carnitine, L-carnitine tartrate

Carnitine shuttles fatty acids into mitochondria, where they are used for energy. The body makes it and we get it mostly from meat.

Forms & use LongevityWeak evidence

L-carnosine

carnosine

Carnosine is a dipeptide of beta-alanine and histidine found in muscle and brain. It acts as an acid buffer and antioxidant and is studied for protection against protein glycation.

Forms & use PerformanceModerate evidence

L-citrulline

citrulline malate

Citrulline is an amino acid the body converts to arginine and then nitric oxide, which helps widen blood vessels. It raises blood arginine more effectively than arginine itself.

Forms & use Amino acidsWeak evidence

L-cysteine

cysteine

L-cysteine is a sulphur amino acid that the body uses to make glutathione and that builds keratin in hair and nails. You normally get it from dietary protein.

Forms & use Amino acidsWeak evidence

L-glutamine

glutamine

Glutamine is the most abundant amino acid in the body and an important fuel for gut and immune cells. Most people on a protein-adequate diet get enough of it.

Forms & use Amino acidsWeak evidence

L-histidine

histidine

Histidine is an essential amino acid the body uses to make histamine and, with beta-alanine, carnosine. As a standalone supplement it is poorly researched.

Forms & use Amino acidsWeak evidence

L-leucine

leucine

Leucine is an essential branched-chain amino acid (BCAA) that acts as the main trigger for muscle protein synthesis. On its own it is not enough for muscle growth; the other amino acids are needed too.

Forms & use Amino acidsWeak evidence

L-lysine

lysine

Lysine is an essential amino acid needed for protein and collagen production and involved in calcium absorption. It is best known for use in recurrent cold sores.

Forms & use Amino acidsNo evidence

L-methionine

methionine

Methionine is an essential sulphur amino acid the body uses to make cysteine, taurine and the methyl donor SAMe. Most people get enough from food.

Forms & use PerformanceNo evidence

L-norvaline

norvaline

Norvaline is a non-protein amino acid that inhibits the enzyme arginase in the lab and might therefore prolong arginine's effect. It is sold mainly as part of pre-workout blends.

Forms & use Amino acidsWeak evidence

L-ornithine

ornithine

Ornithine is a non-essential amino acid of the urea cycle, which helps the body clear ammonia. It is often combined with arginine.

Forms & use Amino acidsWeak evidence

L-phenylalanine

phenylalanine

Phenylalanine is an essential amino acid the body converts to tyrosine and then dopamine and noradrenaline. As a supplement it is poorly researched.

Forms & use Amino acidsNo evidence

L-proline

proline

Proline is a non-essential amino acid that, with glycine, makes up a large share of collagen. The body makes it on its own.

Forms & use Amino acidsWeak evidence

L-serine

serine

Serine is a non-essential amino acid needed to make membrane phospholipids, glycine and D-serine in the brain. The body normally makes it itself.

Forms & use Sleep & calmWeak evidence

L-theanine

theanine

L-theanine is an amino acid from green tea that supports relaxed alertness without sedation. It is often combined with caffeine.

Forms & use Amino acidsNo evidence

L-threonine

threonine

Threonine is an essential amino acid that is a key component of protective gut mucus and of proteins such as collagen and elastin. A normal diet provides enough.

Forms & use Amino acidsWeak evidence

L-tryptophan

tryptophan

Tryptophan is an essential amino acid the body uses to make serotonin and melatonin. Supplements are used mainly to support sleep and mood.

Forms & use Amino acidsWeak evidence

L-tyrosine

tyrosine

Tyrosine is an amino acid the body uses to make dopamine, noradrenaline and thyroid hormones. It is studied mainly for sustaining mental performance under stress.

Forms & use Amino acidsNo evidence

L-valine

valine

Valine is one of the three branched-chain amino acids (BCAAs) with leucine and isoleucine. Muscles can use it as fuel during prolonged exercise.

Forms & use DigestionStrong evidence

Lactase

lactase enzyme, dairy enzymes

Lactase is an enzyme that breaks down milk sugar (lactose) into glucose and galactose. People with lactose intolerance do not produce enough of it in their own gut.

Forms & use OtherWeak evidence

Lactoferrin

milk glycoprotein

Lactoferrin is an iron-binding protein found naturally in breast milk, colostrum and, in smaller amounts, cow's milk. Supplements are made from cow's milk and are often combined with iron or vitamin C.

Forms & use Sleep & calmModerate evidence

Lavender

lavender oil capsules

Lavender has a long tradition as a calming herb. Standardised lavender oil in capsules is one of the better-studied herbs for mild anxiety.

Forms & use OtherWeak evidence

Lecithin

soy lecithin, sunflower lecithin

Lecithin is a mix of phospholipids, mainly phosphatidylcholine, sourced from soy, sunflower or eggs. It provides choline and is also used as an emulsifier in foods.

Forms & use Sleep & calmWeak evidence

Lemon balm

Melissa officinalis

Lemon balm is a lemon-scented herb of the mint family, traditionally used for calm, sleep and digestion. It is often combined with L-theanine, valerian or lavender.

Forms & use DigestionWeak evidence

Licorice

DGL, deglycyrrhizinated licorice, Glycyrrhiza glabra

Licorice is the root of Glycyrrhiza glabra, which contains glycyrrhizin. The DGL form has the glycyrrhizin removed and is mainly used to soothe the stomach and oesophageal lining.

Forms & use Adaptogens & herbsWeak evidence

Lion's mane

Hericium erinaceus

Lion's mane is an edible mushroom containing hericenones and erinacines, which are studied for supporting nerve cell growth. Human evidence so far comes from small studies.

Forms & use OtherWeak evidence

Liver support complex

liver detox, liver blend

Liver support complexes combine several herbs and nutrients traditionally associated with the liver. The effect depends on the specific composition and the doses of each ingredient.

Forms & use OtherNo evidence

Lomatium

Lomatium dissectum

Lomatium is a North American herb whose root was traditionally used for respiratory infections. Human clinical studies are practically absent, so its effect is not established.

Forms & use LongevityNo evidence

Longevity complex

epigenetic complex, anti-ageing complex

Longevity or 'epigenetic' complexes typically combine NAD+ precursors (NMN, nicotinamide riboside), resveratrol, quercetin or fisetin, spermidine, trimethylglycine, curcumin, ergothioneine or B vitamins. Quality depends on the composition and doses on the label; there is no human evidence that they extend life or 'reverse epigenetic age'.

Forms & use Amino acidsWeak evidence

Lupin protein

lupin bean protein

Lupin protein is made from sweet lupin seeds, a legume high in protein and fibre and low in starch. It has a neutral taste and is also used in food production.

Forms & use OtherModerate evidence

Lutein

lutein and zeaxanthin, meso-zeaxanthin, eye carotenoids

Lutein and zeaxanthin are yellow carotenoids from leafy greens and egg yolk that accumulate in the macula of the retina. They filter blue light and protect the eye from oxidative damage.

Forms & use Adaptogens & herbsWeak evidence

Maca

Lepidium meyenii, Peruvian ginseng

Maca is a root vegetable from the Peruvian Andes, eaten as food and taken as a supplement. Small studies suggest effects on libido and wellbeing, but not on hormone levels.

Forms & use MineralsModerate evidence

Magnesium

Mg

Magnesium is a mineral involved in more than 300 enzyme reactions, including energy production and muscle and nerve function. Low intake is common with diets low in vegetables, legumes and nuts, and under stress or heavy training.

Forms & use Sleep & calmWeak evidence

Magnolia bark

Magnolia officinalis, honokiol

Magnolia bark is used in traditional Chinese medicine and contains honokiol and magnolol, which act on GABA receptors. In supplements it is used for stress and sleep.

Forms & use LongevityWeak evidence

Maitake

hen-of-the-woods, Grifola frondosa

Maitake is an edible mushroom containing beta-glucans such as the so-called D-fraction. Its effects on immunity and blood sugar are being studied, but human evidence is still weak.

Forms & use PerformanceStrong evidence

Maltodextrin

glucose polymer

Maltodextrin is a carbohydrate made by partial breakdown of starch (usually maize) with a neutral taste and fast absorption. It is used in sports drinks and gainers as an energy source during and after exercise.

Forms & use MineralsWeak evidence

Manganese

Mn

Manganese is a trace element needed for connective tissue and bone formation and for the antioxidant enzyme superoxide dismutase. A normal diet with whole grains, nuts, legumes and tea provides plenty, so deficiency is rare.

Forms & use OtherWeak evidence

Manuka honey

Leptospermum scoparium honey

Manuka honey comes from New Zealand and Australia and contains methylglyoxal (MGO), which is credited with antibacterial activity. The best evidence is for topical use on wounds; benefits when taken by mouth are poorly proven.

Forms & use DigestionWeak evidence

Marshmallow root

Althaea officinalis

Marshmallow root is rich in mucilage that forms a protective layer on mucous membranes. The European Medicines Agency recognises its traditional use for dry cough, throat irritation and mild stomach complaints.

Forms & use PerformanceModerate evidence

Mass gainer

weight gainer, carb-protein shake

A mass gainer is a powdered blend of carbohydrates (mainly maltodextrin, sometimes oats or sugars) and protein, often with fats, creatine or vitamins. It helps raise energy intake when gaining weight is hard; ratios and quality depend on the label.

Forms & use OtherModerate evidence

Matcha

powdered green tea

Matcha is finely ground green tea from shade-grown leaves that is consumed whole rather than steeped. It contains caffeine, L-theanine and catechins (mainly EGCG), so it is stimulating but usually calmer than coffee.

Forms & use PerformanceWeak evidence

MCT oil

medium-chain triglycerides

MCTs are shorter-chain fats (mainly C8 and C10) that are absorbed quickly and readily converted to ketones in the liver. They are mostly used on ketogenic diets as a fast energy source.

Forms & use OtherModerate evidence

Meal replacement

meal replacement shake, diet shake

A meal replacement is a powder for a drink that combines protein, carbohydrates, fats, fibre, vitamins and minerals in a defined calorie amount. Composition varies by manufacturer, so quality depends on the label.

Forms & use Sleep & calmModerate evidence

Melatonin

sleep hormone

Melatonin is a hormone the body produces in the evening darkness that signals it is time to sleep. As a supplement it mainly helps with falling asleep and shifting the body clock.

Forms & use OtherWeak evidence

Milk thistle

silymarin, Silybum marianum

Milk thistle contains silymarin, a mixture of flavonolignans with antioxidant properties. It is the best-known liver herb, but clinical trial results are inconsistent.

Forms & use OtherWeak evidence

Mistletoe

European mistletoe, Viscum album

Mistletoe is a semi-parasitic plant whose herb is traditionally used to support blood pressure and circulation. It contains lectins and viscotoxins; evidence for the effects of oral supplements in humans is weak.

Forms & use MineralsWeak evidence

Molybdenum

Mo, molybdate

Molybdenum is a trace element that is part of enzymes processing sulphur amino acids, purines and some compounds in the liver. It is found in legumes, grains and nuts, and deficiency is very rare on a normal diet.

Forms & use OtherWeak evidence

Moringa

Moringa oleifera, moringa powder

Moringa is a tropical tree whose dried, ground leaves are sold as a green powder or in capsules. It provides protein, fibre, some minerals and polyphenols, but at usual doses it acts more like a food addition than a major nutrient source.

Forms & use OtherWeak evidence

MSM

methylsulfonylmethane, organic sulphur

MSM (methylsulfonylmethane) is an organic sulphur compound found in small amounts in foods. It is sold to support joints and recovery, but studies are small and short.

Forms & use Adaptogens & herbsWeak evidence

Mucuna pruriens

velvet bean, cowhage, L-DOPA

Mucuna pruriens is a tropical legume whose seeds naturally contain L-DOPA, the precursor of dopamine. It is sold for mood, motivation and libido; L-DOPA is also a medicine, so caution is needed.

Forms & use PerformanceWeak evidence

Muira puama

Ptychopetalum olacoides, "potency wood"

Muira puama is an Amazonian tree whose bark and roots are traditionally used to support libido and energy. Human research is very limited and mostly old.

Forms & use MineralsModerate evidence

Multimineral

mineral complex

A multimineral combines several minerals, typically magnesium, calcium, zinc, iron, selenium, copper, manganese, chromium and iodine. It works as a safety net for a limited diet, but quality and doses vary widely, so check the label.

Forms & use VitaminsWeak evidence

Multivitamin

multivitamin and mineral complex

A combination supplement providing several vitamins, often with minerals or plant extracts, in one dose. It can help fill dietary gaps but does not replace a varied diet.

Forms & use Adaptogens & herbsWeak evidence

Mushroom blend

medicinal mushroom complex

Medicinal mushroom blends combine several mushroom species in one product. The effect depends on the species included, their doses and whether fruiting body extract or mycelium is used.

Forms & use Amino acidsModerate evidence

NAC – N-acetylcysteine

N-acetyl-L-cysteine

NAC is a more stable form of the amino acid cysteine that the body uses to make glutathione, the main intracellular antioxidant. Medically it is used to loosen mucus and in paracetamol poisoning.

Forms & use LongevityWeak evidence

NADH / NAD+

nicotinamide adenine dinucleotide, NAD+, NADH

NAD+ and its reduced form NADH are coenzymes that cells need for energy production and repair processes; their levels decline with age. Supplements offer NADH/NAD+ directly or their precursors, but human evidence of benefit is still limited.

Forms & use OtherWeak evidence

Nasturtium

garden nasturtium, Tropaeolum majus

Garden nasturtium is a plant whose herb contains glucosinolates that release benzyl isothiocyanate, an antimicrobial compound. In some countries it is used in combination with horseradish for urinary and respiratory infections.

Forms & use OtherWeak evidence

Nattokinase

natto enzyme

Nattokinase is an enzyme from natto, a traditional Japanese food made from fermented soybeans. It is studied for its ability to break down fibrin and support circulation, but human evidence is limited.

Forms & use LongevityWeak evidence

Nicotinamide riboside

NR, NAD+ precursor, a form of vitamin B3

Nicotinamide riboside is a form of vitamin B3 that the body turns into the coenzyme NAD+, important for energy production and DNA repair. NAD+ levels decline with age, which is why NR is studied as a supplement for healthy ageing.

Forms & use LongevityWeak evidence

NMN (nicotinamide mononucleotide)

β-NMN, NAD+ precursor

NMN is a molecule the body uses to make NAD+ – a coenzyme needed for energy production in mitochondria and for cellular repair. NAD+ levels decline with age, which is why NMN is one of the best-known longevity and biohacking supplements.

Forms & use OtherWeak evidence

Nootropic complex

nootropics, brain booster

Nootropic complexes are blends of compounds intended to support focus, memory and mental performance. The effect depends on the specific composition and doses, and good studies of the blends themselves are rare.

Forms & use OtherWeak evidence

Olive leaf extract

olive leaf, oleuropein

Olive leaf extract is rich in oleuropein and hydroxytyrosol, polyphenols with antioxidant activity. It is studied for blood pressure and blood sugar; antimicrobial effects are shown mainly in the lab.

Forms & use Omega-3 & fatsWeak evidence

Omega 3-6-9

omega-3, -6 and -9 blend

A blend of fish and plant oils (flaxseed, sunflower, olive, borage or evening primrose) supplying different fatty acids. Most people already get enough omega-6 and omega-9 from food.

Forms & use Omega-3 & fatsStrong evidence

Omega-3 fatty acids

fish oil, EPA and DHA

EPA and DHA are long-chain fats from fish and algae that are built into cell membranes of the heart, brain and retina. The body makes them from plant ALA only in small amounts.

Forms & use OtherWeak evidence

Oregano oil

oil of oregano, carvacrol

Oregano oil is a concentrated essential oil from oregano, high in carvacrol and thymol. In the lab it acts against bacteria and fungi, but clinical evidence in humans is very limited.

Forms & use LongevityWeak evidence

Oyster mushroom

Pleurotus ostreatus

Oyster mushroom is a common edible mushroom rich in beta-glucans (pleuran), fibre and ergothioneine. It also naturally contains small amounts of lovastatin, so it is studied for effects on cholesterol.

Forms & use VitaminsNo evidence

PABA

para-aminobenzoic acid, "vitamin B10"

PABA is a compound some bacteria use to make folate; it is not a vitamin for humans, although it is sometimes called "vitamin B10". It is sold for hair, skin and greying, but evidence is lacking.

Forms & use Sleep & calmWeak evidence

Passionflower

Passiflora incarnata, maypop

Passionflower is a herb whose aerial parts are traditionally used for calm and better sleep. It contains flavonoids that probably act via the GABA system.

Forms & use Amino acidsModerate evidence

Pea protein

pea protein isolate

Pea protein is made from yellow peas and is rich in lysine and arginine but lower in methionine. It is free of lactose, gluten and soy and is one of the most popular plant proteins.

Forms & use LongevityNo evidence

Phellinus

Phellinus linteus, meshima

Phellinus linteus is a wood-decaying mushroom used in Korean and Japanese traditional medicine. It contains polysaccharides and polyphenols studied in the lab, but clinical evidence in humans is almost absent.

Forms & use LongevityWeak evidence

Phosphatidylserine

PS

Phosphatidylserine is a phospholipid and an important part of cell membranes, especially in the brain. Supplements are now made from soy or sunflower and are used for memory and coping with stress.

Forms & use LongevityWeak evidence

Pine bark extract

maritime pine, Pinus pinaster, OPC, proanthocyanidins

Maritime pine bark extract is rich in proanthocyanidins (OPC) and other polyphenols. It is studied mainly for supporting blood vessels, circulation and skin.

Forms & use OtherModerate evidence

Piperine

black pepper extract, Piper nigrum

Piperine is the alkaloid that gives black pepper its pungency. In supplements it is added mainly to improve the absorption of other compounds, especially curcumin.

Forms & use Amino acidsModerate evidence

Plant protein blend

vegan protein, plant protein

Plant protein blends combine several sources, typically pea, rice, hemp, pumpkin, soy or sunflower, to complement amino acids. Ratios, protein content and additives vary, so quality depends on the label.

Forms & use OtherWeak evidence

Policosanol

octacosanol, sugar cane alcohols, plant waxes

Policosanol is a mixture of long-chain alcohols from sugar cane wax, beeswax or rice. Original studies from a single source showed lower cholesterol, but independent studies have mostly not confirmed this.

Forms & use LongevityWeak evidence

Polyphenol blend

polyphenol complex, antioxidant blend

Polyphenol blends combine polyphenol-rich extracts, typically from grape (OPC, resveratrol), green tea (EGCG), pine bark, pomegranate, olive or berries. Their effect and quality depend on the exact composition and doses on the label; the evidence relates to individual ingredients rather than the blends themselves.

Forms & use DigestionWeak evidence

Postbiotics

inactivated bacteria, fermentation products, paraprobiotics

Postbiotics are preparations of non-living (heat-inactivated) microorganisms or their components and metabolites. Unlike probiotics they do not need to survive in the gut, are more stable and need no refrigeration.

Forms & use MineralsModerate evidence

Potassium

K

Potassium is the main mineral inside cells and, together with sodium, regulates fluid balance, nerve signals and muscle function including the heart. The best sources are vegetables, fruit, legumes and potatoes; supplements contain only small doses.

Forms & use PerformanceModerate evidence

Pre-workout blend

pre-workout stimulant, pre-workout shot

A pre-workout is a blend taken before training, typically containing caffeine, beta-alanine, citrulline, creatine, betaine, tyrosine and electrolytes. Its effect comes mainly from individual ingredients at adequate doses, so quality depends on the label.

Forms & use DigestionModerate evidence

Prebiotic fibre

resistant dextrin, soluble corn fibre, GOS, PHGG

Prebiotic fibre is an umbrella term for non-digestible carbohydrates that ferment in the large intestine and feed beneficial bacteria. Examples include resistant dextrin, galacto-oligosaccharides (GOS) and partially hydrolysed guar gum.

Forms & use DigestionModerate evidence

Probiotics

probiotic bacteria, lactobacilli, bifidobacteria

Probiotics are live microorganisms that, in adequate amounts, can benefit health. The effect depends on the specific strain, not just the bacterial species.

Forms & use Amino acidsStrong evidence

Protein blend

multi-protein, multi-component protein

A protein blend combines fast- and slow-digesting proteins, typically whey, casein and sometimes egg or soy protein. The ratio varies, so quality depends on the label.

Forms & use Amino acidsWeak evidence

Protein shot

liquid protein ampoule

A protein shot is a small liquid serving of protein (usually around 20–25 g) in an ampoule, often based on collagen hydrolysate, sometimes whey. It is handy on the go, but protein quality depends on the source on the label.

Forms & use DigestionStrong evidence

Psyllium

psyllium husk, ispaghula, blond plantain

Psyllium is the seed husk of Plantago ovata, rich in soluble gel-forming fibre. It swells in water, softens stools and slows the absorption of sugars and fats from a meal.

Forms & use OtherWeak evidence

Pumpkin seed (extract, oil)

pumpkin seed extract, pumpkin seed oil

Pumpkin seed extract and oil are used for bladder complaints and an enlarged prostate. The seeds contain phytosterols, zinc and fatty acids.

Forms & use Amino acidsWeak evidence

Pumpkin seed protein

pumpkin protein

Pumpkin seed protein is made from defatted pumpkin seeds and contains about 50–65% protein plus fibre and minerals such as magnesium, iron and zinc. It has a mild nutty taste and a green colour.

Forms & use OtherWeak evidence

Pygeum (African plum)

Prunus africana, African cherry

Pygeum is an extract from the bark of the African tree Prunus africana, containing phytosterols and triterpenes. It is used mainly for urinary symptoms linked to an enlarged prostate.

Forms & use LongevityWeak evidence

Quercetin

flavonoid

Quercetin is a flavonoid found naturally in onions, apples, capers and tea. It is studied for antioxidant, anti-inflammatory and antihistamine properties, but human evidence is limited.

Forms & use OtherNo evidence

Raspberry ketones

raspberry ketone, rheosmin

Raspberry ketone is the aroma compound that gives raspberries their smell; in supplements it is almost always synthetic. It is promoted as a fat burner based on cell and animal experiments, while good human studies are lacking.

Forms & use OtherWeak evidence

Red clover

Trifolium pratense

Red clover contains isoflavones (biochanin A, formononetin) with weak oestrogen-like activity, similar to soy isoflavones. It is used mainly for menopausal symptoms.

Forms & use OtherModerate evidence

Red yeast rice

red fermented rice, monacolin K

Red yeast rice is made by fermenting rice with the mould Monascus purpureus and contains monacolins – monacolin K is chemically identical to the drug lovastatin. At higher monacolin doses it lowers LDL cholesterol, but because of safety concerns its monacolin content is restricted in the EU.

Forms & use Adaptogens & herbsWeak evidence

Reishi

Ganoderma lucidum, lingzhi

Reishi is a hard, wood-decaying mushroom from traditional Asian medicine containing beta-glucans and triterpenes. It is used to support immunity, calm and sleep, but good human evidence is limited.

Forms & use OtherWeak evidence

Respiratory complex

airway complex, respiratory support blend

Respiratory complexes typically combine N-acetylcysteine (NAC), vitamin C, zinc, vitamin D, and extracts of ivy, thyme, ribwort plantain, marshmallow, elderberry or quercetin. Their effect and quality depend on the composition and doses on the label; liposomal forms are said to improve absorption, but independent evidence is limited.

Forms & use LongevityWeak evidence

Resveratrol

trans-resveratrol, Japanese knotweed, grape polyphenol

Resveratrol is a polyphenol from grape skins, peanuts and Japanese knotweed that became famous through animal experiments on ageing. In humans it is absorbed quickly but also broken down quickly, and study results are inconsistent.

Forms & use Adaptogens & herbsWeak evidence

Rhodiola

Rhodiola rosea, golden root

Rhodiola is a northern herb whose root is traditionally used for fatigue and stress. Studies suggest a modest effect on stress-related fatigue, but they are small and inconsistent.

Forms & use Amino acidsWeak evidence

Rice protein

brown rice protein

Rice protein is extracted mainly from brown rice and is hypoallergenic, gluten-free and soy-free. It is lower in lysine, so it is often combined with pea protein.

Forms & use OtherWeak evidence

Rosemary

Salvia rosmarinus, Rosmarinus officinalis

Rosemary is a culinary herb rich in rosmarinic and carnosic acid, which have antioxidant activity. It is traditionally used for digestion, circulation and focus.

Forms & use OtherWeak evidence

Royal jelly

bee royal jelly

Royal jelly is a nutritious secretion produced by worker bees to feed the queen; it contains protein, sugars, the fatty acid 10-HDA and B vitamins. It is sold for energy and immunity, but good human evidence is limited.

Forms & use OtherWeak evidence

Rutin

rutoside, "vitamin P", flavonoid

Rutin is a flavonoid found in buckwheat, citrus fruit, apples and black tea. It is often combined with vitamin C and used to support blood vessels and venous circulation.

Forms & use DigestionModerate evidence

Saccharomyces boulardii

probiotic yeast, S. boulardii

Saccharomyces boulardii is a probiotic yeast which, unlike bacteria, is not sensitive to antibiotics. It is one of the best-studied probiotics, especially for preventing antibiotic-associated diarrhoea.

Forms & use OtherModerate evidence

Saffron

saffron extract

Saffron is a spice from the stigmas of Crocus sativus; extracts are standardised for compounds such as crocin and safranal. It is one of the better-studied herbs for mild low mood.

Forms & use OtherWeak evidence

Sage

common sage, Salvia officinalis

Common sage is a culinary and medicinal herb containing rosmarinic acid and essential oils, including thujone. It is traditionally used for excessive sweating, sore throat and digestion.

Forms & use Amino acidsModerate evidence

SAMe

S-adenosylmethionine, ademetionine

SAMe is a compound the body makes from the amino acid methionine; it donates methyl groups for hundreds of reactions, including neurotransmitter production. In some countries it is also used as a medicine.

Forms & use OtherWeak evidence

Saw palmetto

Serenoa repens, sabal

Saw palmetto is a palm whose berries are made into a lipid extract used for an enlarged prostate. However, large good-quality trials have not shown a clear benefit over placebo.

Forms & use Adaptogens & herbsWeak evidence

Schisandra

Schisandra chinensis, five-flavour berry

Schisandra is a vine whose berries ("five-flavour fruit") are used as an adaptogen in traditional Chinese and Russian medicine. It contains lignans (schisandrins), studied mainly for effects on the liver.

Forms & use MineralsWeak evidence

Seaweed blend

sea vegetables, kelp, bladderwrack, InSea2, alkaline blend

These are powders or extracts of several seaweeds such as kelp, bladderwrack, wakame, dulse or lithothamnion. They supply iodine and minerals; brown seaweed extracts (e.g. InSea2) are studied for blood sugar after meals. Composition varies widely, so quality depends on the label.

Forms & use MineralsModerate evidence

Selenium

Se

Selenium is a trace element that forms part of antioxidant enzymes and of the enzymes that activate thyroid hormones. Central European soils are relatively low in selenium, yet only small amounts are needed – for example a couple of Brazil nuts.

Forms & use OtherNo evidence

Shark cartilage

cartilage from sharks

Shark cartilage is dried, powdered cartilage from sharks that naturally contains chondroitin sulfate, collagen and minerals. It is sold mainly for joint support, but convincing human evidence of benefit is lacking.

Forms & use LongevityWeak evidence

Shiitake

Lentinula edodes

Shiitake is an edible mushroom native to East Asia that contains beta-glucans (e.g. lentinan), ergothioneine and vitamin D (when exposed to UV light). As a supplement it is used mainly for immune support.

Forms & use Adaptogens & herbsWeak evidence

Shilajit

mumijo, mineral pitch

Shilajit is a resin-like substance from mountain rocks, rich in fulvic acid and minerals, used in Ayurveda. Modern studies are small and few.

Forms & use MineralsWeak evidence

Silicon

Si, silica, horsetail

Silicon is a trace element found in grains (especially oats and barley), beer, mineral waters and the horsetail plant. It is involved in connective tissue and bone formation, but its essentiality for humans is not firmly established.

Forms & use DigestionWeak evidence

Slippery elm

Ulmus rubra, red elm

The inner bark of the North American slippery elm is rich in mucilage, which forms a protective gel with water. It is traditionally used to soothe an irritated throat, oesophagus and stomach.

Forms & use OtherModerate evidence

Soy isoflavones

genistein, daidzein, phytoestrogens

Soy isoflavones (genistein, daidzein, glycitein) are plant compounds with weak oestrogen-like activity, found in soy and soy foods. They are used mainly to ease hot flushes in menopause.

Forms & use Amino acidsModerate evidence

Soy protein

soy isolate, SPI

Soy protein is a plant protein with a complete essential amino-acid profile, mostly sold as an isolate with over 85–90% protein. It contains isoflavones and is one of the best-studied plant proteins.

Forms & use LongevityWeak evidence

Spermidine

polyamine, wheat germ extract

Spermidine is a natural polyamine found in wheat germ, soy, mushrooms and aged cheese that promotes autophagy – the cellular clean-up of damaged parts. Animal experiments are promising, but human data are still limited.

Forms & use OtherWeak evidence

Spirulina

Arthrospira platensis, blue-green algae

Spirulina is a blue-green cyanobacterium (Arthrospira) rich in protein, iron, beta-carotene and the pigment phycocyanin. It is taken as a "superfood" supplement, but health benefits are supported only by small studies.

Forms & use OtherStrong evidence

St John's wort

Hypericum perforatum

St John's wort is a herb whose extracts contain hyperforin and hypericin. For mild to moderate depressive symptoms it is one of the best-studied herbs, but it has many serious drug interactions.

Forms & use OtherWeak evidence

Stinging nettle

Urtica dioica, nettle leaf and root

Nettle is used in two distinct forms: the leaf as a mild diuretic and for joints, and the root for urinary symptoms with an enlarged prostate. The leaf is also a source of minerals and vitamin K.

Forms & use LongevityWeak evidence

Sulforaphane

broccoli extract, broccoli sprout extract

Sulforaphane is a sulphur compound formed from glucoraphanin in broccoli and its sprouts by the enzyme myrosinase. It is studied as an activator of the Nrf2 pathway, which switches on the cells' own antioxidant and detoxification defences.

Forms & use Amino acidsWeak evidence

Sunflower protein

sunflower seed protein

Sunflower protein is obtained from defatted sunflower seeds and is free of soy, gluten and dairy. It contains protein, fibre and vitamin E; the taste is mildly nutty and slightly bitter.

Forms & use PerformanceWeak evidence

Synephrine

p-synephrine, bitter orange, Citrus aurantium

Synephrine is a stimulant from bitter orange peel, chemically related to ephedrine but with a weaker effect. It is added to fat burners and pre-workout blends to increase energy expenditure.

Forms & use OtherWeak evidence

Systemic enzymes

proteolytic enzymes, enzyme therapy

Systemic enzymes are blends of protein-digesting enzymes (typically bromelain, papain, trypsin, chymotrypsin, serrapeptase), often with rutin. They are taken on an empty stomach to influence inflammation and swelling; composition and quality depend on the label.

Forms & use Sleep & calmWeak evidence

Tart cherry

sour cherry, Montmorency

Tart cherry is rich in anthocyanins and contains small amounts of melatonin. It is used as a concentrate or extract to support sleep and recovery after exertion.

Forms & use Amino acidsWeak evidence

Taurine

L-taurine

Taurine is an amino sulfonic acid abundant in the heart, muscles, brain and retina. The body can make it, and it is also found in meat and fish.

Forms & use PerformanceWeak evidence

Testosterone booster (complex)

T-booster, testosterone support

Testosterone boosters are blends of minerals and plant extracts, typically zinc, magnesium, vitamin D, D-aspartic acid, tribulus, fenugreek, ashwagandha or tongkat ali. Raised testosterone is convincing mainly when zinc or vitamin D is deficient; the blend's quality depends on the label.

Forms & use OtherWeak evidence

Thyme

garden thyme, Thymus vulgaris

Thyme contains an essential oil with thymol and carvacrol, which act against microbes and loosen mucus. The European Medicines Agency recognises its traditional use for coughs associated with colds.

Forms & use MineralsWeak evidence

Thyroid support complex

thyroid support blend

These are blends of nutrients and herbs aimed at the thyroid – typically iodine (often from kelp), selenium, zinc, L-tyrosine and sometimes ashwagandha or guggul. Composition varies widely, so quality and suitability depend on the label.

Forms & use VitaminsWeak evidence

Tocotrienols

vitamin E (tocotrienols), delta- and gamma-tocotrienol

Tocotrienols are lesser-known forms of vitamin E found mainly in annatto, palm and rice bran oil. They act as fat-soluble antioxidants; their specific benefits in humans are only weakly supported so far.

Forms & use PerformanceWeak evidence

Tribulus terrestris

puncture vine

Tribulus is a plant traditionally used for libido and vitality, today mainly in products for men and athletes. Extracts are standardised to saponins (protodioscin), but studies have not confirmed higher testosterone in humans.

Forms & use OtherModerate evidence

Trimethylglycine

TMG, betaine

Trimethylglycine (betaine) is found in beetroot, spinach and whole grains and acts as a methyl donor in the body. It helps convert homocysteine into methionine.

Forms & use DigestionWeak evidence

Triphala

Ayurvedic three-fruit blend

Triphala is a traditional Ayurvedic blend of three dried fruits: amalaki, bibhitaki and haritaki. It is mainly used as gentle support for regular bowel movements.

Forms & use LongevityModerate evidence

Turmeric

curcumin, Curcuma longa

Turmeric is the root of Curcuma longa, and its main active compound is curcumin, which has anti-inflammatory and antioxidant properties. Curcumin on its own is very poorly absorbed, so the form matters.

Forms & use OtherWeak evidence

Uric acid support blend

gout blend, celery and cherry

These blends target uric acid levels, typically with celery seed and tart cherry extract, sometimes with quercetin, nettle or vitamin C. Composition varies widely, so quality depends on the label.

Forms & use LongevityWeak evidence

Urolithin A

UA

Urolithin A is produced in the gut when bacteria process ellagitannins from pomegranate, nuts or strawberries; however, not everyone produces enough of it. It is studied for effects on mitochondrial renewal (mitophagy) and muscle function, but human evidence is still limited.

Forms & use Sleep & calmWeak evidence

Valerian

valerian root

Valerian is a traditional herb whose root is used for calming and sleep support. Study results are mixed and any effect usually appears only after a few weeks.

Forms & use OtherWeak evidence

Vegan collagen builder

plant-based collagen support

Vegan "collagen" products do not contain collagen – collagen is an animal protein only. They are typically a mix of amino acids (glycine, proline, lysine), vitamin C, zinc, copper, silicon and plant extracts that the body is meant to use to make its own collagen; quality depends on the label.

Forms & use VitaminsModerate evidence

Vitamin A

retinol

Vitamin A is a fat-soluble vitamin needed for night vision, healthy skin and mucous membranes and immunity. Deficiency is rare in Europe, and because vitamin A is stored in the liver, excess from supplements can be harmful.

Forms & use VitaminsModerate evidence

Vitamin B1

thiamine

Vitamin B1 is needed to turn carbohydrates into energy and for normal nerve and heart function. Deficiency is mainly a risk with heavy alcohol use, long-term diuretic use, after bariatric surgery and with very restricted diets.

Forms & use VitaminsStrong evidence

Vitamin B12

cobalamin

Vitamin B12 is needed for red blood cell formation, nerve function and DNA synthesis. It occurs naturally only in animal foods, so a supplement is essential on a vegan diet and often needed in older people and with certain medicines.

Forms & use VitaminsModerate evidence

Vitamin B2

riboflavin

Vitamin B2 is involved in cellular energy production, iron metabolism and protecting cells from oxidative stress. At high doses it is studied for migraine prevention.

Forms & use VitaminsModerate evidence

Vitamin B3

niacin, nicotinamide

Vitamin B3 is part of the coenzymes NAD and NADP, which are essential for energy production and DNA repair. It exists as nicotinic acid, which causes flushing, and nicotinamide, which does not.

Forms & use VitaminsWeak evidence

Vitamin B5

pantothenic acid, pantethine

Vitamin B5 is part of coenzyme A, which is key for fat metabolism and the production of energy and stress hormones. It is found in almost all foods, so deficiency is very rare.

Forms & use VitaminsModerate evidence

Vitamin B6

pyridoxine

Vitamin B6 is involved in protein metabolism, the production of neurotransmitters (serotonin, dopamine, GABA) and the regulation of hormonal activity. Deficiency is rare, but long-term excess from supplements can damage nerves.

Forms & use VitaminsModerate evidence

Vitamin C

ascorbic acid

Vitamin C is a water-soluble antioxidant needed for immunity, collagen formation and iron absorption. Humans cannot make it, but a varied diet with vegetables and fruit usually covers it.

Forms & use VitaminsModerate evidence

Vitamin D2

ergocalciferol

Vitamin D2 is the plant form of vitamin D, mainly obtained from UV-exposed mushrooms and yeast. It has the same role as D3 but raises and maintains blood vitamin D levels less effectively.

Forms & use VitaminsStrong evidence

Vitamin D3

cholecalciferol

Vitamin D3 is made in the skin in sunlight and is needed for calcium absorption, healthy bones, muscles and immunity. At central European latitudes the sun is too weak to make it from October to March, so low winter levels are very common.

Forms & use VitaminsWeak evidence

Vitamin E

tocopherol

Vitamin E is a fat-soluble antioxidant that protects cell membranes from oxidative damage. Deficiency is rare because vegetable oils, nuts and seeds are rich sources.

Forms & use VitaminsModerate evidence

Vitamin K1

phylloquinone

Vitamin K1 is the main dietary form of vitamin K, found mostly in leafy greens. It is essential for producing blood clotting factors and also supports bone health.

Forms & use VitaminsWeak evidence

Vitamin K2

menaquinone, MK-7

Vitamin K2 activates proteins that bind calcium into bone and take part in blood clotting. It is found in fermented foods (natto, cheese); the long-acting MK-7 form stays in the blood longer than K1.

Forms & use VitaminsModerate evidence

Vitamins ADEK

fat-soluble vitamin complex

Vitamins ADEK combine the four fat-soluble vitamins – A, D, E and K – in one capsule. They are used mainly with fat malabsorption (e.g. cystic fibrosis, pancreatic disease or after bowel surgery), where deficiency of these vitamins is common.

Forms & use OtherModerate evidence

Vitex (chasteberry)

chaste tree, Vitex agnus-castus, monk's pepper

Vitex is an extract from the fruit of the chaste tree that acts on the hormonal axis via dopamine receptors and influences prolactin levels. It is mainly used for premenstrual syndrome and breast tenderness.

Forms & use Amino acidsStrong evidence

Whey protein

whey, WPC, WPI

Whey protein is obtained from whey during cheese making and is one of the highest-quality proteins, rich in leucine. It digests quickly, making it practical for topping up protein after training or during the day.

Forms & use OtherWeak evidence

White kidney bean extract

Phaseolus vulgaris, starch blocker, alpha-amylase inhibitor

White kidney bean extract contains compounds that partly inhibit alpha-amylase, the enzyme that breaks down starch. Some starch from a meal may therefore go undigested, which is why it is sold as a "carb blocker".

Forms & use OtherModerate evidence

White willow (bark)

Salix alba, willow bark

White willow bark contains salicin, which the body converts into compounds related to salicylic acid. It is traditionally used for back and joint pain; the effect is slower and milder than with painkillers.

Forms & use OtherNo evidence

Wild yam

Dioscorea villosa, diosgenin

Wild yam is a tuber containing diosgenin, which is used in the lab to manufacture steroid hormones. The human body, however, cannot convert diosgenin into progesterone or other hormones, so claims of "natural progesterone" are not true.

Forms & use LongevityWeak evidence

Wood ear mushroom

Auricularia auricula-judae, jelly ear, mu-err

Wood ear is an edible mushroom popular in Asian cooking, rich in polysaccharides and soluble fibre. It is traditionally linked to circulation support, but human evidence is weak.

Forms & use DigestionWeak evidence

Wormwood

Artemisia absinthium

Wormwood is a very bitter herb whose bitter compounds stimulate digestive juices and bile. It also contains thujone, which is toxic to the nervous system at higher doses; the European Medicines Agency recognises only short-term traditional use for digestive complaints.

Forms & use PerformanceModerate evidence

Yerba mate

mate, Ilex paraguariensis

Yerba mate is a South American drink made from the leaves of a holly species, containing caffeine, theobromine and polyphenols (chlorogenic acid). It is stimulating, similar to coffee or tea.

Forms & use OtherWeak evidence

Zeolite (clinoptilolite)

clinoptilolite, activated zeolite

Zeolite is a porous volcanic mineral that can bind certain substances and ions. It is sold for "detox", but a benefit from routine use in healthy people has not been convincingly shown.

Forms & use MineralsModerate evidence

Zinc

Zn

Zinc is a trace element important for immunity, wound healing, skin, hair and hormone production including testosterone. The body has no real storage for it, so it needs a regular dietary supply.

Forms & use MineralsWeak evidence

ZMA / ZMB6

zinc, magnesium and vitamin B6

ZMA (ZMB6) is a combination of zinc, magnesium and vitamin B6, popular with athletes and taken in the evening. The individual nutrients have proven roles, but claims of higher testosterone or performance have not held up in people without deficiency.

Forms & use