Benefits
Strength and high-intensity exercise performance
Meta-analyses of placebo-controlled trials show creatine improves strength in efforts under 3 minutes: effect size 0.24 for the legs across 60 trials and 0.32 for the upper body across 53 trials, regardless of age, sex or training. A 100-study analysis found small gains in short, intense tasks, largest in repeated lab resistance efforts, with no clear benefit for running or swimming.
Lean body mass and muscle growth
With resistance training, creatine added more lean mass than training alone: 1.37 kg more in a meta-analysis of 22 trials in 721 older adults, along with better chest press and leg press strength. Across 100 studies in mixed groups, the effect on body composition (body mass and lean mass) was small (effect size 0.17).
Recovery between training sessions
The International Society of Sports Nutrition reports that research suggests creatine may enhance recovery after exercise and help athletes tolerate heavy training loads. The trials summarized on this page measured strength, performance and lean mass rather than recovery itself.
Memory, with clearer effects in older adults
A meta-analysis of 16 trials in 492 adults found better memory with creatine monohydrate (SMD 0.31, moderate certainty), faster attention and processing times (low certainty) and no change in overall cognition or executive function. In healthy people, another analysis found a memory gain in adults aged 66 to 76 but almost none in people aged 11 to 31.
Thinking during sleep loss
In 15 healthy young adults, a single large dose (0.35 g per kg) taken during a night of partial sleep deprivation shifted brain energy markers and improved cognitive performance and processing speed compared with placebo. It is a small trial of a dose far above everyday use.
Water in muscle and early weight gain
Loading with about 20 g a day for 5 to 7 days typically adds 1 to 3 kg of body mass, mostly water. Over longer periods, studies suggest creatine does not change total body water relative to muscle mass, and it does not increase fat mass.
Safety in healthy people
Expert reviews conclude that at recommended doses creatine does not cause kidney damage in healthy people, dehydration, muscle cramps or hair loss, and is not an anabolic steroid. Intakes up to 30 g a day for up to 5 years were well tolerated in studies. Several review authors have ties to creatine makers.
Mechanism of action
Phosphocreatine and fast energy
When ATP is used for muscle work, the breakdown of phosphocreatine supplies energy to rebuild it. This helps keep ATP available during maximal sprint-type efforts. Supplements raise muscle creatine and phosphocreatine by about 20% to 40%.
Where creatine comes from
About half of the daily need comes from food, mainly red meat and seafood; the rest is made in the liver and kidneys from arginine and glycine. About 95% is stored in skeletal muscle, and about 1% to 2% breaks down to creatinine each day.
Water inside muscle cells
Creatine draws water into muscle cells early in supplementation. Water inside the cell acts as a signal for protein synthesis, which may contribute to muscle gains over time.
Brain energy
Creatine is part of brain energy metabolism, but uptake into the brain is limited, so usual doses act over weeks. Higher doses for longer periods may be needed to raise brain creatine than to fill muscle stores.
Monohydrate and other forms
Clinical evidence has not shown that creatine salts, creatine serum, ethyl ester, buffered forms or creatine nitrate are retained better than creatine monohydrate, and expert reviews conclude other forms are not superior.
Clinical trials
Evidence review and official position of the International Society of Sports Nutrition (Kreider et al. 2017, J Int Soc Sports Nutr)
Studies in athletes, healthy adults and patient groups from infants to older adults
Concludes that creatine monohydrate is the most effective ergogenic nutritional supplement available to athletes for increasing high-intensity exercise capacity and lean body mass during training, and that short and long-term intakes up to 30 g a day for 5 years were safe and well tolerated in healthy people and many patient groups.
Meta-analysis of 100 randomized, placebo-controlled, blinded studies (Branch 2003, Int J Sport Nutr Exerc Metab)
Healthy men and women, trained and untrained
Effects were small but significant for body composition, meaning body mass and lean body mass (effect size 0.17), and for short tasks of 30 seconds or less (0.24). Effects were larger for repeated lab-based and upper-body tasks, did not differ by sex or training status, and creatine did not appear to improve running or swimming.
Systematic review and meta-analysis of 60 randomized placebo-controlled studies (Lanhers et al. 2015, Sports Med)
646 people on creatine and 651 controls
Creatine improved lower-limb strength in efforts under 3 minutes: global effect size 0.235 (95% CI 0.125 to 0.346), squat 0.336 and leg press 0.297. Meta-regression found no link with age, sex, dose or training protocol.
Systematic review and meta-analysis of 53 randomized placebo-controlled studies (Lanhers et al. 2017, Sports Med)
563 people on creatine and 575 controls
Creatine improved upper-limb strength in efforts under 3 minutes: global effect size 0.317 (95% CI 0.185 to 0.449), bench press 0.265. Results did not depend on population, dose or training protocol.
Meta-analysis of 22 randomized controlled trials of creatine or placebo during resistance training 2 to 3 days a week for 7 to 52 weeks (Chilibeck et al. 2017, Open Access J Sports Med)
721 men and women, mean age 57 to 70 across studies
Creatine added 1.37 kg more lean tissue mass (95% CI 0.97 to 1.76) and improved chest press (SMD 0.35) and leg press strength (SMD 0.24) compared with placebo. The outcomes were lean mass and strength.
Systematic review and meta-analysis of 16 randomized controlled trials, all using creatine monohydrate (Xu et al. 2024, Front Nutr)
492 adults aged 20.8 to 76.4, healthy and with specific diseases
Creatine improved memory (SMD 0.31, moderate certainty), attention time (SMD -0.31) and processing speed time (SMD -0.51), the last two of low certainty, with no significant effect on overall cognition or executive function. Benefits were larger in people with diseases, those aged 18 to 60 and women.
Systematic review of 10 randomized placebo-controlled trials, 8 pooled (Prokopidis et al. 2023, Nutr Rev)
Healthy people aged 11 to 76
Creatine improved memory overall (SMD 0.29, 95% CI 0.04 to 0.53, I2 66%). The gain was clear in adults aged 66 to 76 (SMD 0.88) but near zero in people aged 11 to 31 (SMD 0.03). Dose (about 2.2 to 20 g a day), duration (5 days to 24 weeks) and sex did not change the result.
Placebo-controlled study of one oral dose of creatine monohydrate (0.35 g per kg) with brain MR spectroscopy and cognitive tests during 21 hours of sleep deprivation (Gordji-Nejad et al. 2024, Sci Rep)
15 healthy adults aged 20 to 28
Creatine changed brain high-energy phosphate measures, prevented a drop in brain pH and improved cognitive performance and processing speed. It is one small study of a very high single dose.
Evidence review by an expert panel answering 12 common questions (Antonio et al. 2021, J Int Soc Sports Nutr)
Literature of over 500 peer-reviewed publications
Concludes that at recommended doses creatine does not cause kidney damage in healthy people, dehydration, muscle cramping or fat gain, is not an anabolic steroid, is not linked to hair loss by most evidence, that 3 to 5 g a day works without loading, and that other forms are not superior to monohydrate. Several authors report ties to creatine manufacturers.