Magnesium
A mineral the body needs for muscles, nerves, blood sugar, blood pressure and bones. Sold as glycinate, citrate, oxide and other forms.
- Why people take it
- Sleep, muscle cramps, stress and constipation (citrate and oxide have a laxative effect).
- What the evidence says
- Helps if you are low in it. For sleep and cramps in people who are not low, studies show small or no benefit.
- Be careful
- Too much from supplements causes diarrhoea; adults should not take more than 350 mg a day from supplements unless a doctor advises. Avoid with kidney disease. Take it at least 2 hours apart from some antibiotics and osteoporosis medicines.
- In food
- Nuts, seeds, whole grains, dals and beans, leafy greens.
Read more: NIH Office of Dietary Supplements: magnesium β
π Full page for Magnesium
Vitamin D (D3)
A vitamin the skin makes in sunlight. It helps the body absorb calcium for strong bones and keeps muscles working.
- Why people take it
- Bone health, immunity and low vitamin D levels, which are common in India despite the sun.
- What the evidence says
- Clearly useful if you are deficient. For people with normal levels, studies have not shown that extra vitamin D prevents fractures, infections or other illness.
- Be careful
- Get your level tested before taking high doses. Too much over months raises blood calcium, which can harm the kidneys and heart. Adults should not go above 4,000 IU (100 mcg) a day without medical advice.
- In food
- Sunlight, oily fish, egg yolk, fortified milk.
Read more: NIH Office of Dietary Supplements: vitamin D β
π Full page for Vitamin D (D3)
Protein powder
Concentrated protein from milk (whey, casein), soy, peas or other plants.
- Why people take it
- Building muscle with exercise, feeling full, and getting enough protein.
- What the evidence says
- Helps muscle gain when combined with strength training if your diet is short of protein. Most people can get enough protein from food.
- Be careful
- Talk to your doctor if you have kidney disease. Check for added sugar, and choose brands tested by an independent lab, as some products have been found with contaminants.
- In food
- Milk, curd, paneer, eggs, dals, soy, chicken and fish.
Read more: NIH Office of Dietary Supplements: supplements for exercise β
π Full page for Protein powder
Omega-3 / fish oil
Fats called EPA and DHA from oily fish, or ALA from plants such as flax seeds and walnuts.
- Why people take it
- Heart health, brain health and inflammation.
- What the evidence says
- High prescription doses lower triglycerides. For most people, ordinary fish oil capsules have not clearly prevented heart attacks or strokes. Eating fish twice a week is still recommended.
- Be careful
- Can increase bleeding with blood thinners such as warfarin. High doses are linked to a higher risk of an irregular heartbeat (atrial fibrillation). Fishy burps and upset stomach are common.
- In food
- Oily fish (mackerel, sardines, salmon), walnuts, flax and chia seeds.
Read more: NIH Office of Dietary Supplements: omega-3 fatty acids β
π Full page for Omega-3 / fish oil
Creatine (monohydrate)
A compound made in the body and found in meat and fish, stored in muscles for short bursts of energy.
- Why people take it
- Strength, power and muscle gain in the gym and sports; more recently, brain function.
- What the evidence says
- One of the best-studied supplements: it helps repeated short, intense efforts and muscle gain with training. Effects on thinking and memory are still being researched.
- Be careful
- Causes some weight gain from water in the muscles. Talk to your doctor if you have kidney disease. It raises creatinine in blood tests, which can be mistaken for a kidney problem, so tell your doctor you take it.
- In food
- Meat and fish.
Read more: NIH Office of Dietary Supplements: supplements for exercise β
π Full page for Creatine (monohydrate)
Ashwagandha
A herb (Withania somnifera) long used in Ayurveda; the root is sold as powder or extract.
- Why people take it
- Stress, anxiety, sleep and energy.
- What the evidence says
- Small, short studies suggest it may lower stress and improve sleep a little. Long-term effects are not known.
- Be careful
- Rare cases of liver injury have been reported. Avoid in pregnancy and breastfeeding. Can raise thyroid hormone levels and may add to the effect of sedatives. Not for people with autoimmune disease or before surgery without asking a doctor.
Read more: NIH Office of Dietary Supplements: ashwagandha β
π Full page for Ashwagandha
Collagen
Protein from animal skin, bones or fish scales, sold as hydrolysed collagen peptides.
- Why people take it
- Skin, hair, nails and joints.
- What the evidence says
- Some studies show small improvements in skin elasticity and joint pain, but many are funded by makers. The body breaks collagen down into amino acids like any other protein.
- Be careful
- Not vegetarian. Choose a tested brand; some collagen products have been found with heavy metals.
- In food
- Bone broth, chicken and fish with skin; any protein-rich food provides the building blocks.
Read more: Harvard Health: can collagen powder improve your skin? β
π Full page for Collagen
Probiotics
Live bacteria and yeasts (such as Lactobacillus, Bifidobacterium and Saccharomyces boulardii) similar to those in the gut.
- Why people take it
- Gut health, digestion, diarrhoea and immunity.
- What the evidence says
- Some strains help prevent diarrhoea from antibiotics. Effects depend on the exact strain, and for most other uses the evidence is mixed.
- Be careful
- Avoid if you are seriously ill or have a weak immune system (for example during chemotherapy) unless your doctor agrees.
- In food
- Curd (dahi), yogurt, buttermilk, idli and dosa batter, and other fermented foods.
Read more: NIH Office of Dietary Supplements: probiotics β
π Full page for Probiotics
Iron
A mineral the body needs to make haemoglobin, which carries oxygen in the blood.
- Why people take it
- Tiredness and anaemia, which is very common in India, especially among women and children.
- What the evidence says
- Treats iron-deficiency anaemia. Taking it without being low does not boost energy.
- Be careful
- Take only if a blood test (haemoglobin, ferritin) shows you are low. Too much is harmful, and iron tablets can poison young children, so keep them out of reach. Causes constipation and dark stools. Take apart from tea, coffee and calcium; vitamin C helps absorption.
- In food
- Meat, fish, eggs, dals and beans, leafy greens, ragi.
Read more: NIH Office of Dietary Supplements: iron β
π Full page for Iron
Multivitamins
Tablets with a mix of vitamins and minerals, often close to daily needs.
- Why people take it
- Covering gaps in the diet.
- What the evidence says
- Useful when the diet is poor, in pregnancy (prenatal vitamins) and for some older adults. For well-fed adults, they have not been shown to prevent heart disease or cancer.
- Be careful
- Do not double up with other supplements that contain the same nutrients. Too much vitamin A is harmful in pregnancy.
- In food
- A varied diet with vegetables, fruit, whole grains, dals, milk and protein foods.
Read more: NIH Office of Dietary Supplements: multivitamin/mineral supplements β
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Zinc
A mineral needed for immunity, wound healing, taste and smell.
- Why people take it
- Colds, immunity, skin and recovery.
- What the evidence says
- Zinc lozenges started within a day of a cold may shorten it a little. Supplements help children with diarrhoea in low-income settings (as part of ORS treatment).
- Be careful
- More than 40 mg a day for long periods can cause copper deficiency. Zinc nasal sprays have caused loss of smell. May cause nausea.
- In food
- Meat, shellfish, dals and beans, nuts and seeds, whole grains.
Read more: NIH Office of Dietary Supplements: zinc β
π Full page for Zinc
Vitamin C
A vitamin that acts as an antioxidant, helps make collagen and improves iron absorption.
- Why people take it
- Immunity, colds and skin.
- What the evidence says
- Taking it regularly may shorten colds slightly but does not prevent them for most people.
- Be careful
- More than 2,000 mg a day can cause diarrhoea and raises the risk of kidney stones in some people.
- In food
- Amla, guava, citrus fruits, tomatoes, capsicum.
Read more: NIH Office of Dietary Supplements: vitamin C β
π Full page for Vitamin C
CoQ10 / Ubiquinol
Coenzyme Q10, a compound the body makes and uses to produce energy in cells. Ubiquinol is one form of it.
- Why people take it
- Energy, heart health, ageing, and muscle aches from statin medicines.
- What the evidence says
- Studied in heart failure, migraine and statin muscle pain, with mixed results. Not proven to boost energy in healthy people.
- Be careful
- May make warfarin less effective and can lower blood pressure. Talk to your doctor if you take heart or blood-pressure medicines.
- In food
- Meat, fish, whole grains.
Read more: Mayo Clinic: coenzyme Q10 β
π Full page for CoQ10 / Ubiquinol
Fibre (psyllium / isabgol)
The part of plant foods the body cannot digest. Psyllium husk (isabgol) is a common soluble fibre supplement.
- Why people take it
- Constipation, digestion, cholesterol, blood sugar and feeling full.
- What the evidence says
- Psyllium helps constipation and lowers LDL cholesterol a little. Most people eat less fibre than recommended (about 25 g a day or more).
- Be careful
- Drink plenty of water with it, or it can cause blockage. Take medicines 2 hours apart from fibre supplements, as fibre can reduce their absorption. Start slowly to avoid gas and bloating.
- In food
- Whole grains, dals and beans, vegetables, fruit, nuts.
Read more: MedlinePlus: dietary fiber β
π Full page for Fibre (psyllium / isabgol)
Berberine
A yellow compound from plants such as Indian barberry (daruharidra), goldenseal and Chinese goldthread (huanglian).
- Why people take it
- Blood sugar, cholesterol and weight; online it is sometimes called "nature's Ozempic".
- What the evidence says
- Some studies show it lowers blood sugar and cholesterol a little. Weight loss in studies is small, and it does not work like Ozempic.
- Be careful
- Can cause stomach upset and constipation. Interacts with many medicines and can make blood sugar too low with diabetes medicines. Not safe in pregnancy, breastfeeding or for newborns.
Read more: NCCIH: berberine β
π Full page for Berberine
B vitamins / B12 / B-complex
A group of vitamins the body uses to turn food into energy; B12 also keeps nerves and blood cells healthy.
- Why people take it
- Energy, nerves and B12 deficiency.
- What the evidence says
- B12 supplements are important for vegetarians and vegans, older adults and people on metformin or acid-reducing medicines, who often run low. Extra B vitamins do not boost energy if you are not deficient.
- Be careful
- B12 is generally safe. High doses of vitamin B6 over a long time can damage nerves.
- In food
- B12: milk, curd, paneer, eggs, meat, fish. Other B vitamins: whole grains, dals, leafy greens.
Read more: NIH Office of Dietary Supplements: vitamin B12 β
π Full page for B vitamins / B12 / B-complex
Vitamin K2
Vitamin K helps blood clot and builds bone proteins. K1 comes from leafy greens; K2 from fermented foods and animal foods.
- Why people take it
- Bone health, often taken together with vitamin D3.
- What the evidence says
- Research on whether K2 prevents fractures or heart disease is limited and mixed.
- Be careful
- If you take warfarin, do not start or stop vitamin K without your doctor, as it changes how the medicine works.
- In food
- K1: spinach, methi and other leafy greens. K2: natto, cheese, eggs.
Read more: NIH Office of Dietary Supplements: vitamin K β
π Full page for Vitamin K2
L-theanine
An amino acid found in tea leaves.
- Why people take it
- Calm focus, stress and sleep, often taken with caffeine.
- What the evidence says
- Small studies suggest it may help relaxation and attention, especially with caffeine, but good-quality evidence is limited.
- Be careful
- Usually well tolerated. Talk to your doctor if you take blood-pressure medicines or sedatives.
- In food
- Green and black tea.
Read more: NCCIH: using dietary supplements wisely β
π Full page for L-theanine
Turmeric / Curcumin
The yellow spice and curcumin, its main active compound. Curcumin is poorly absorbed, so supplements often add black pepper extract (piperine).
- Why people take it
- Inflammation, joint pain and as an antioxidant.
- What the evidence says
- There is little reliable evidence that turmeric supplements prevent or treat any disease. Some studies show a small effect on knee arthritis pain.
- Be careful
- High-dose supplements, especially with piperine, have been linked to liver injury. Avoid with gallstones and talk to your doctor if you take blood thinners. Turmeric in cooking is safe.
- In food
- Turmeric in food (haldi).
Read more: NCCIH: turmeric β
π Full page for Turmeric / Curcumin
Calcium
The main mineral in bones and teeth, also needed for muscles and nerves.
- Why people take it
- Bone health and preventing osteoporosis.
- What the evidence says
- Best taken from food. Supplements help if your diet is low in calcium, for example if you take no dairy, especially for older women.
- Be careful
- More than 2,000 to 2,500 mg a day can cause kidney stones and constipation. Take no more than 500 mg at a time. Take it apart from thyroid medicines, iron and some antibiotics.
- In food
- Milk, curd, paneer, ragi, sesame seeds, leafy greens.
Read more: NIH Office of Dietary Supplements: calcium β
π Full page for Calcium
Electrolytes
Sodium, potassium, magnesium and chloride, sold as powders, tablets and sports drinks.
- Why people take it
- Hydration and recovery after exercise or heat.
- What the evidence says
- Useful for long, hard exercise or heavy sweating. For diarrhoea and vomiting, WHO oral rehydration salts (ORS) are the right choice. For everyday activity, water and food are enough.
- Be careful
- High in sodium: be careful with high blood pressure, heart or kidney disease. Many sports drinks are also high in sugar.
- In food
- Fruit, vegetables, coconut water, a pinch of salt in food.
Read more: MedlinePlus: fluid and electrolyte balance β
π Full page for Electrolytes
Pre-workout
Powder blends taken before exercise, usually with a lot of caffeine plus beta-alanine, creatine, citrulline and other ingredients.
- Why people take it
- Energy, focus and performance in the gym.
- What the evidence says
- Caffeine and creatine have good evidence for performance; many other ingredients do not. Doses in blends are often not listed clearly.
- Be careful
- Some products have 300 mg of caffeine or more a serving: avoid with heart problems, high blood pressure, anxiety or in pregnancy, and not late in the day. Beta-alanine causes harmless tingling. Some products have been found with banned stimulants.
Read more: NIH Office of Dietary Supplements: supplements for exercise β
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NAD+ / NMN / NR
NAD+ is a molecule every cell uses to make energy; levels fall with age. NMN and NR (nicotinamide riboside) are taken to raise it.
- Why people take it
- Longevity, energy and anti-ageing.
- What the evidence says
- They do raise NAD+ levels in the blood, but human studies have not shown clear benefits for ageing, energy or health. Long-term safety is not known.
- Be careful
- Expensive, and quality varies between products. Talk to your doctor first if you have cancer or take other medicines.
Read more: NCCIH: using dietary supplements wisely β Β· NIH Office of Dietary Supplements: health information β
π Full page for NAD+ / NMN / NR
Potassium
A mineral that controls fluid balance and helps nerves, muscles and the heart work.
- Why people take it
- Blood pressure, heart and muscle function.
- What the evidence says
- Eating more potassium-rich food helps lower blood pressure. Most people should raise potassium through food, not supplements.
- Be careful
- Dangerous with kidney disease or with some blood-pressure medicines (ACE inhibitors, ARBs, potassium-sparing diuretics): too much potassium can upset the heart rhythm. Take supplements only if your doctor advises.
- In food
- Bananas, potatoes, coconut water, dals and beans, leafy greens, tomatoes.
Read more: NIH Office of Dietary Supplements: potassium β
π Full page for Potassium
Ginseng (Asian / Korean)
The root of Panax ginseng, one of the best-known herbs in Chinese and Korean traditional medicine; sold as slices, powder, tea and extract.
- Why people take it
- Energy, fatigue, immunity, memory and blood sugar.
- What the evidence says
- Some small studies suggest effects on blood sugar and tiredness, but the evidence is not strong enough to say it works for any condition.
- Be careful
- May lower blood sugar, especially with diabetes medicines, and may interact with warfarin. Can cause sleep problems and headaches. Avoid in pregnancy, breastfeeding and for children.
Read more: NCCIH: Asian ginseng β
π Full page for Ginseng (Asian / Korean)
Astragalus (huangqi)
The root of Astragalus membranaceus, used in traditional Chinese medicine, often with other herbs.
- Why people take it
- Immunity, fatigue and as a general tonic.
- What the evidence says
- There is very little high-quality research in people, so it is not known whether it helps.
- Be careful
- May interact with medicines that suppress the immune system. Talk to a doctor if you have an autoimmune disease or take regular medicines.
Read more: NCCIH: astragalus β
π Full page for Astragalus (huangqi)
Reishi (lingzhi)
A medicinal mushroom (Ganoderma) used in Chinese medicine for centuries; sold as slices, powder, spore powder and extract.
- Why people take it
- Immunity, sleep, longevity, and support during cancer treatment.
- What the evidence says
- Most research is in the lab or small human studies. There is no reliable evidence that it treats cancer or any other disease.
- Be careful
- Rare cases of liver injury have been linked to reishi powder. May lower blood pressure and blood sugar and increase bleeding with blood thinners. Tell your cancer doctor before using it during treatment.
Read more: National Cancer Institute: medicinal mushrooms β
π Full page for Reishi (lingzhi)
Cordyceps (dongchong xiacao)
A fungus that grows on caterpillars in the Tibetan plateau. Wild cordyceps is very expensive; most products use mycelium grown in factories (such as Cs-4).
- Why people take it
- Energy, stamina, lungs and kidneys, and as a tonic.
- What the evidence says
- Evidence in people is limited and mostly from small studies of the cultivated form.
- Be careful
- In 2016 China's food and drug regulator warned that cordyceps products can contain high levels of arsenic and ended their trial use in health foods. Wild cordyceps is often faked. Talk to a doctor if you take immune-suppressing medicines.
β οΈ No official health-agency page found for this one yet. Please check with a doctor or pharmacist before taking it.
π Full page for Cordyceps (dongchong xiacao)
Goji berries (gouqi)
The dried red berries of Lycium barbarum, eaten as a food and used in Chinese medicine; also sold as juice and extract.
- Why people take it
- Eyesight, immunity, ageing and as a tonic.
- What the evidence says
- A nutritious food rich in antioxidants. Studies of health effects are small, so benefits beyond good nutrition are not proven.
- Be careful
- May increase the effect of warfarin (reported cases of bleeding risk) and may lower blood sugar. People allergic to some fruits may react.
- In food
- Eaten as a dried fruit, in tea and in soups.
β οΈ No official health-agency page found for this one yet. Please check with a doctor or pharmacist before taking it.
π Full page for Goji berries (gouqi)
Red yeast rice (hongqu)
Rice fermented with Monascus yeast, used in Chinese cooking and medicine. It naturally contains monacolin K, the same substance as the cholesterol medicine lovastatin.
- Why people take it
- Lowering cholesterol.
- What the evidence says
- Products with monacolin K do lower LDL cholesterol, because they act like a statin medicine. The amount varies a lot between products.
- Be careful
- It can cause the same side effects as statins (muscle pain, liver problems). Do not take it with statins, in pregnancy, or with liver disease. Some products contain citrinin, a toxin that harms the kidneys. In 2024 red yeast rice (beni-koji) products in Japan were linked to kidney disease and deaths.
Read more: Mayo Clinic: red yeast rice β
π Full page for Red yeast rice (hongqu)
Glucosamine (and chondroitin)
Substances found in cartilage. Glucosamine is usually made from shellfish shells; chondroitin from animal cartilage.
- Why people take it
- Joint pain and knee osteoarthritis.
- What the evidence says
- A large NIH-funded trial found that, overall, they did not relieve knee arthritis pain better than a placebo. Some people report benefit.
- Be careful
- Avoid glucosamine if you are allergic to shellfish. May increase bleeding with warfarin. People with diabetes should check their blood sugar.
Read more: NCCIH: glucosamine and chondroitin β
π Full page for Glucosamine (and chondroitin)
Bird's nest (yanwo)
Nests made by swiftlets from their saliva, cleaned, cooked and eaten as a soup or drink; popular in China, Hong Kong and Southeast Asia.
- Why people take it
- Skin, immunity, recovery and during pregnancy.
- What the evidence says
- There is very little research in people. Nutritionally it is mostly protein, in small amounts per serving.
- Be careful
- Very expensive and often faked or treated with chemicals (for example dyed "blood nests" with high nitrite levels). Can cause allergic reactions. Buy only from trusted sellers with clear labels.
- In food
- Eaten as a sweet soup.
β οΈ No official health-agency page found for this one yet. Please check with a doctor or pharmacist before taking it.
π Full page for Bird's nest (yanwo)
Folic acid
A B vitamin (folate) needed to make new cells and DNA.
- Why people take it
- Planning a pregnancy and early pregnancy, and anaemia.
- What the evidence says
- Strong evidence: taking 400 mcg a day from before conception through early pregnancy greatly lowers the risk of serious birth defects of the brain and spine (neural tube defects).
- Be careful
- Generally safe at usual doses. More than 1,000 mcg a day can hide a vitamin B12 deficiency. Some women need a higher dose on a doctor's advice.
- In food
- Leafy greens, beans and dals, citrus fruits, fortified foods.
Read more: NIH Office of Dietary Supplements: folate β
π Full page for Folic acid