Creatine

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By Nikola · Precision Nutrition L1 · Updated 5 November 2026

Creatine is a compound your body makes from three amino acids and stores almost entirely in muscle, where it helps produce ATP, the fast energy behind short, hard efforts. It is one of the most studied supplements in sport. Taken as creatine monohydrate, it raises muscle stores and in many trials improves strength, power and repeated sprints, while it does little for endurance. The usual dose is 3-5 g a day, with or without a 5-7 day loading phase of 20 g a day. The side effect most people notice is weight gain of about 1-2 kg, partly water.

What the research says

Your liver and kidneys make about 1 g of creatine a day from glycine, arginine and methionine, and almost all of the body’s creatine sits in skeletal and heart muscle (NIH ODS). Supplements top those stores up.

• Strength, power and repeated sprints – strong evidence. NIH ODS: 5-7 days of creatine often significantly increases strength, power, work in repeated maximal sets and sprint performance, and weeks or months of use support gains from structured training. The International Society of Sports Nutrition (ISSN) calls creatine monohydrate “the most effective ergogenic nutritional supplement currently available” for high-intensity exercise capacity and lean body mass.
• Endurance – little benefit. In mostly aerobic exercise lasting more than 150 seconds creatine is not the main energy pathway, and the extra weight may hold you back (NIH ODS).
• Older adults – moderate evidence, with training. Meta-analyses reviewed by the ISSN found larger gains in muscle mass, strength and function when older adults combined creatine with resistance training. Most of the benefit comes from creatine plus training; creatine alone does less (ISSN, 2021).
• Memory and the brain – early research. A 2023 meta-analysis of 8 randomised trials found a small improvement in memory (standardised mean difference 0.29), clearer in people aged 66-76 and absent in people aged 11-31, with results varying a lot between studies. Large trials in Parkinson’s disease and ALS showed no clinical benefit. Treat this as early research, not a reason to start.
• What the EU allows. Regulation (EU) 432/2012 permits “Creatine increases physical performance in successive bursts of short-term, high intensity exercise” for foods giving 3 g a day and aimed at adults doing high-intensity exercise. A second claim, “Daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over the age of 55”, requires 3 g a day plus resistance training at least three times a week for several weeks, with increasing workload, at 65-75% of one-repetition maximum.
• Not shown. No other form has beaten monohydrate. And creatine is not an anabolic steroid: different structure, different mechanism, different legal status.

Dose and forms

• With loading. 20 g a day in four 5 g portions for 5-7 days, then 3-5 g a day (NIH ODS). The ISSN puts loading at about 0.3 g per kg of body weight; larger athletes may need 5-10 g a day to maintain stores.
• Without loading. 3 g a day for about 28 days fills stores more slowly, so the effect also comes later (ISSN).
• Form. Monohydrate is the most studied and clinically effective form. Citrate, ethyl ester, buffered creatine, nitrate and liquid “serum” have not shown greater retention in muscle (ISSN).
• With food. Carbohydrate, or carbohydrate and protein, may increase uptake, but the performance gain may be no greater than with monohydrate alone (ISSN). Stirring it into breakfast, say oats with Greek yogurt, is an easy routine, not a requirement.
• Upper range. The ISSN found no compelling evidence of harm at up to 30 g a day for 5 years. That is a safety finding, not a target.

Food sources

Creatine comes mainly from red meat and seafood. You need roughly 1-3 g a day, about half from food and the rest made by your body; a typical diet with 1-2 g a day leaves muscle stores about 60-80% full (ISSN).

Food	Creatine per pound (454 g)	Creatine per 100 g
Pork	2.3 g	0.51 g
Beef	2 g	0.44 g
Salmon	2 g	0.44 g

Source: NIH ODS, Dietary Supplements for Exercise and Athletic Performance, checked 5 November 2026; per 100 g values calculated and rounded. The ISSN gives about 1-2 g per pound of uncooked beef and salmon. USDA FoodData Central does not list creatine, so there are no FDC values here.

So food rarely reaches supplement doses: 3 g would take about 680 g of beef a day. Lean beef, salmon, mackerel and sardines remain the natural sources, and because meat is a dietary source, supplements may matter more for vegetarians (ISSN, 2021).

Side effects and interactions

• Weight gain. The only side effect reported consistently. Strength training with creatine added 1-2 kg of body weight in a month (NIH ODS), and loading causes short-term fluid retention of about 0.5-1.0 litre (ISSN). Longer studies found no change in body water relative to muscle mass.
• Stomach and muscles. There are anecdotal reports of nausea, diarrhoea and cramps (NIH ODS), but controlled studies, including one that tracked injuries in football players, found less cramping and fewer heat illnesses in creatine users.
• Kidneys in healthy people. At recommended doses creatine does not damage healthy kidneys. It can raise creatinine in blood and urine, the marker labs use to estimate kidney function, so tell your doctor you take it before a kidney test.
• Hair loss. Most evidence does not support a link; the one study reporting higher DHT has not been replicated.
• Medicines. Ask your doctor or pharmacist whether anything you take could interact with a performance supplement (NIH ODS).

Who should avoid it

• People with kidney disease. The myth is that creatine harms healthy kidneys; it does not. With existing kidney disease, the ISSN notes some experts advise seeing a physician first “in an abundance of caution”. Do not start without your doctor.
• Teenagers without supervision. The ISSN finds creatine acceptable for young athletes who train under supervision, eat a balanced diet and stay within recommended doses. NIH ODS advises teens to talk to a health professional first.
• Endurance athletes watching weight. Extra kilograms may cost more than the benefit.
• Pregnancy and breastfeeding. Pregnancy appears in the research only as an area of study, so ask your doctor.

How to choose a good product

• Read the label. “Creatine monohydrate” as the only active ingredient, with grams per serving. Many sports products use proprietary blends that hide the amount of each ingredient (NIH ODS).
• Look for independent testing. The US FDA has warned that some performance supplements contain undeclared stimulants, steroids or drugs. NSF Certified for Sport, Informed-Choice and BSCG test for banned substances; certified products carry the logo and are listed on the certifier’s website (NIH ODS).
• Skip the upgrades. “Advanced” forms have not shown better retention than monohydrate.

FAQ

Is creatine bad for your kidneys?

Not in healthy people at recommended doses: ISSN reviews found no kidney damage, including in long-term users. Creatine can raise blood creatinine, which may look like a kidney problem on a lab test, so tell your doctor you take it. If you already have kidney disease, talk to your doctor before starting.

Do I need a loading phase for creatine?

No. Loading with 20 g a day for 5-7 days fills muscle stores fastest, while 3 g a day gets there in about four weeks. Loading only makes sense if you want the effect sooner.

Does creatine cause water retention?

In the short term, yes: loading can add about 0.5-1.0 litre of fluid, and many people gain 1-2 kg in the first month of training with creatine. Longer studies found no change in body water relative to muscle mass.

Related entries and articles

• Whey protein – the other supplement most used with strength training
• Collagen – what the evidence says for joints and skin
• High-protein diets
• Salmon, mackerel and sardines
• Magnesium
• High-protein vegetarian breakfast ideas
• Baked salmon with root vegetables

Sources

1. NIH Office of Dietary Supplements: Dietary Supplements for Exercise and Athletic Performance, Fact Sheet for Health Professionals (page modified 25 October 2026). ods.od.nih.gov
2. NIH Office of Dietary Supplements: Dietary Supplements for Exercise and Athletic Performance, Fact Sheet for Consumers. ods.od.nih.gov
3. Kreider RB, Kalman DS, Antonio J, et al. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition 14(1). doi:10.1186/s12970-017-0173-z. doaj.org
4. Antonio J, Candow DG, Forbes SC, et al. (2021). Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition 18:13. doi:10.1186/s12970-021-00412-w. europepmc (ebi.ac.uk)
5. Prokopidis K, Giannos P, Triantafyllidis KK, et al. (2023). Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. doi:10.1093/nutrit/nuac064. read.qxmd.com
6. Commission Regulation (EU) No 432/2012 – permitted health claims (creatine). legislation.gov.uk

This page is for information only and is not medical or dietary advice.