Supplements
Every supplement we cover. Each page rates the evidence for individual claims and shows safety information first.
Showing 1–5 of 50 supplements, page 1 of 10
- Alpha-lipoic acid
Other · Reviewed
A sulfur-containing compound that the body makes and foods hold in tiny amounts, widely used for nerve damage from diabetes and studied for blood sugar.
- Ashwagandha
Herbal · Reviewed
An evergreen shrub used in Ayurvedic medicine for thousands of years. Its supplements are promoted for stress and anxiety, sleep, and athletic performance.
- Astaxanthin
Other · Reviewed
A red-orange pigment made by algae and found in salmon, trout and shellfish. Trials have tested it for skin aging, tired eyes, exercise and cholesterol.
- BCAAs (branched-chain amino acids)
Amino acid · Reviewed
Leucine, isoleucine and valine, three essential amino acids found in protein foods. People take them as supplements for sore muscles, muscle growth and sport.
- Berberine
Herbal · Reviewed
A yellow compound found in plants such as barberry and goldenseal. People take it for blood sugar, cholesterol, weight and polycystic ovary syndrome.
- Betaine (TMG)
Other · Reviewed
A compound in beets, spinach and seafood, also called TMG, sold as a supplement. Trials have tested it for homocysteine, body fat and endurance.
- Biotin
Vitamin · Reviewed
A B vitamin found in foods such as eggs, organ meats, fish, nuts and seeds, and often promoted in supplements for hair, skin and nail health.
- Cinnamon
Herbal · Reviewed
A spice made from the dried bark of Cinnamomum trees, including cassia and Ceylon cinnamon. As a supplement, it is promoted for diabetes and weight loss.
- Coenzyme Q10
Other · Reviewed
A compound the body makes, found in almost every cell. It has been put forward for heart failure, statin muscle aches, high blood pressure and migraine.
- Collagen
Other · Reviewed
The body's most abundant structural protein, made into supplements from cattle, pig, fish or poultry. It is studied for skin, joints, muscle and bone.
- Creatine
Other · Reviewed
A compound the body makes in the liver and kidneys and gets from meat and fish. People who lift weights often take it hoping to build muscle and strength.
- DHEA
Other · Reviewed
A hormone made by the adrenal glands that the body turns into testosterone and estrogen. People take it for sex drive, menopause, fertility, aging and muscle.
- Echinacea
Herbal · Reviewed
Echinacea, or purple coneflower, is a North American plant related to daisies and sunflowers, sold mostly for the common cold and other respiratory infections.
- Folate (folic acid)
Vitamin · Reviewed
A B vitamin in leafy greens, beans and fortified grains. Many US adults take it, and a US task force recommends folic acid for people who could become pregnant.
- Ginkgo
Herbal · Reviewed
Ginkgo is an ancient tree, called a living fossil, whose leaf extract is promoted for memory and thinking, dementia, tinnitus and many other conditions.
- Glucosamine
Other · Reviewed
An amino sugar found in cartilage, made for supplements from shellfish shells or grain, and taken for osteoarthritis and joint pain.
- Glutathione
Other · Reviewed
A small molecule the body makes from three amino acids. People take it by mouth hoping to lighten their skin.
- Iodine
Mineral · Reviewed
A trace mineral the thyroid uses to make its hormones, found in seaweed, fish, dairy and iodised salt, and taken as a supplement in pregnancy.
- L-arginine
Amino acid · Reviewed
An amino acid in protein-rich foods such as nuts and animal products, which the body also makes. It is sold in supplements for exercise and erections.
- L-carnitine
Amino acid · Reviewed
A compound the body makes from amino acids and gets from foods such as red meat. People take it as a supplement for weight loss, exercise, fertility and memory.
- L-citrulline
Amino acid · Reviewed
An amino acid the body makes and watermelon contains. A 2026 review describes citrulline malate as a supplement marketed to aid exercise performance.
- L-theanine
Amino acid · Reviewed
An amino acid found mainly in tea leaves and sold on its own as a supplement. People take it for stress, sleep and focus, sometimes with caffeine.
- Licorice root
Herbal · Reviewed
Licorice root comes from a herb grown across Europe, Asia and the Middle East and flavors sweets. It is promoted for digestive and respiratory support.
- Lion’s mane
Other · Reviewed
An edible mushroom long used in traditional Chinese medicine, now sold and promoted for memory, anxiety and depression.
- Magnesium
Mineral · Reviewed
A mineral found in green leafy vegetables, nuts, seeds and whole grains. It is sold as a supplement for sleep and for muscle cramps.
- Melatonin
Other · Reviewed
A hormone the brain makes in response to darkness, also made synthetically and sold in the US as a supplement that adults and children take as a sleep aid.
- Methylene blue
Other · Reviewed
A blue dye approved in the US as a prescription injection for acquired methemoglobinemia. Its label warns of serotonin syndrome with opioids and serotonergic drugs, including many antidepressants.
- N-acetylcysteine (NAC)
Amino acid · Reviewed
A derivative of the amino acid cysteine, sold as a supplement and also approved as a drug. It has been studied for COPD, substance cravings and mental health.
- Nattokinase
Other · Reviewed
An enzyme first isolated from natto, a Japanese fermented soybean food. People take it hoping to lower blood pressure or cholesterol, or break down clots.
- Nicotinamide riboside
Vitamin · Reviewed
A form of vitamin B3 sold as a supplement. It has drawn interest for possible "anti-ageing" effects through raising NAD+, a molecule cells need.
- NMN (nicotinamide mononucleotide)
Other · Reviewed
A building block the body uses to make NAD+, a molecule cells use to produce energy. It is promoted with claims about aging, metabolism and blood sugar.
- Omega-3 fatty acids (fish oil)
Fatty acid · Reviewed
Fats found in oily fish and sold as fish oil, studied for heart disease, triglycerides, depression, memory and thinking, and rheumatoid arthritis.
- Oregano oil
Herbal · Reviewed
An oil from oregano, a mint-family herb used as a spice. It has traditional uses for colds, coughs and infections, and is marketed for general wellness.
- Pomegranate
Herbal · Reviewed
The pomegranate is a small fruit tree from the Middle East with a history in traditional medicine. Today many take its juice or extracts hoping to support blood pressure, heart health and blood sugar.
- Potassium
Mineral · Reviewed
An essential mineral in fruit, vegetables, beans, milk and potatoes, also sold as supplements and in salt substitutes. People take it for blood pressure.
- Probiotics
Other · Reviewed
Live microbes, mostly bacteria and some yeasts, found in some fermented foods and sold as supplements. Studied for diarrhea linked to antibiotics and for IBS.
- Psyllium husk
Other · Reviewed
A fiber from the seed coats of the plant Plantago ovata that swells into a gel in water. It has been studied for constipation, cholesterol, blood sugar and IBS.
- Quercetin
Other · Reviewed
A plant compound found in onions, apples, berries and tea, sold on its own and in products advertised for general health, weight loss and body building.
- Resveratrol
Other · Reviewed
A plant compound found in grapes and red wine, sold as a supplement. It has been put forward for high blood fats, diabetes and aging.
- Spermidine
Other · Reviewed
A natural compound in foods such as wheat germ, mushrooms, cheese and soybean products. It has been tested as a supplement for memory, hair and aging.
- Spirulina
Other · Reviewed
A dried blue-green alga sold as a supplement and added to foods. A US government database lists hay fever, high blood pressure and diabetes among its uses.
- Taurine
Amino acid · Reviewed
A sulfur-containing amino acid in seafood and meat, also added to energy drinks. People take it for exercise, heart health, blood sugar and focus.
- Tongkat ali
Herbal · Reviewed
A Southeast Asian tree used in traditional medicine. Its root extracts are now sold as supplements promoted for testosterone and athletic performance.
- Turmeric and curcumin
Herbal · Reviewed
A yellow spice from a plant in the ginger family, colored by curcumin. It is promoted as a supplement for osteoarthritis, depression and high cholesterol.
- Urolithin A
Other · Reviewed
A compound the gut makes from substances in foods such as pomegranates, walnuts and raspberries. It has been studied for muscle, mitochondria and aging.
- Vitamin B12
Vitamin · Reviewed
A vitamin found naturally in animal foods such as fish, meat, eggs and dairy. In a US survey, 24% of men and 29% of women reported using a supplement with it.
- Vitamin C
Vitamin · Reviewed
An essential vitamin in fruit and vegetables such as citrus and peppers. It is widely sold for colds and promoted for many other conditions.
- Vitamin D
Vitamin · Reviewed
A vitamin the skin makes in sunlight and a few foods contain. Many adults take it, and a 2026 review says it has been widely recommended to prevent fractures.
- Whey protein
Other · Reviewed
Milk proteins from whey, a cheese-making by-product, found in most protein powders. People take it hoping to build muscle, stay strong with age or lose weight.
- Zinc
Mineral · Reviewed
An essential mineral in meat, seafood and fortified cereals. It is sold in cold remedies and in eye supplements marketed for macular degeneration.