GradedHealth

Creatine

Last reviewed October 2026 · Based on 23 studies

Bottom line

Creatine consistently increases muscle strength during resistance training in healthy adults. In postmenopausal women, it gives small gains in lean mass and leg strength when combined with resistance training, and bone density was unchanged overall. In healthy people, trials show no significant change in kidney filtration, though blood creatinine rises slightly. For memory and thinking, the evidence is early and limited.

What it helps with

  • Increases muscle strength during resistance training — Benefit, evidence grade A (Strong). Consistent systematic reviews and meta-analyses of dozens of randomised controlled trials in humans measuring maximal lifting strength. Some authors of the newer meta-analyses have ties to creatine makers or receive creatine donations (PMID 39519498).
  • Builds leg strength in postmenopausal women — Benefit, evidence grade B (Moderate). Meta-analysis of seven RCTs (608 women); downgraded once for small numbers in the strength analysis (three trials, 111 women).
  • Adds lean mass in postmenopausal women — Benefit, evidence grade C (Limited). Meta-analysis of five RCTs (338 women); downgraded for small sample and because lean mass is a surrogate for strength and function; a 2-year trial at 3 g/day found no additional lean-mass gain.
  • Protects bone density in postmenopausal women — No effect, evidence grade B (Moderate). Meta-analysis of seven RCTs (608 women) found bone density unchanged overall; downgraded once for inconsistency, since a small 2015 trial found less femoral neck loss while two larger 2-year trials found none.
  • Damages kidney function in healthy adults — No effect, evidence grade B (Moderate). Trials show no significant change in filtration, but the small creatinine rise is inconsistent across durations (significant at a week or less and beyond 12 weeks, not in between) and the review does not describe people with kidney disease; downgraded once for inconsistency from A.
  • Improves memory performance — Benefit, evidence grade C (Limited). Meta-analyses of 8 to 16 small RCTs; downgraded for inconsistency (high heterogeneity, mixed cognitive domains) and small total sample.
  • Sharpens overall thinking and reasoning — Mixed results, evidence grade C (Limited). Reviews disagree: one found no overall gain, another reported possible gains in reasoning; downgraded for inconsistency and low GRADE certainty.
  • Eases thinking problems after sleep loss — Benefit, evidence grade C (Limited). A single small RCT (29 people) plus a narrative review of five studies; downgraded for small sample and few studies.
  • Causes hair loss — Mixed results, evidence grade C (Limited). Two small trials disagree on DHT (one rise, one no change) and neither measured hair loss over years; downgraded for inconsistency and small samples.
  • Caffeine with creatine may speed Parkinson's progression — Harm, evidence grade C (Limited). Secondary analysis of one large creatine trial in Parkinson's, not designed to test caffeine; downgraded for indirectness and single source.

What it is

Creatine is made in the body from the amino acids arginine, glycine and methionine [1]. Adults get creatine mainly from animal foods such as muscle meat, or from supplements [1]. The form used in all studies of a 2024 cognition review was creatine monohydrate [2].

How it might work

Proposed, not confirmed: creatine plays a key role in brain energy metabolism, and supplements may raise brain creatine stores, which could support memory [3]. Proposed, not confirmed: one 2009 study in rugby players suggested creatine may in part act by increasing the conversion of testosterone to DHT [4].

What the research says

A 2015 meta-analysis of 60 trials found that creatine significantly improved lower-limb strength, with effect sizes of 0.336 for squat and 0.297 for leg press [5]. A 2026 meta-analysis of 63 randomised controlled trials involving 1,489 participants found that combining creatine with resistance training significantly increased upper-body strength (Hedges' g = 0.54) and lower-body strength (Hedges' g = 0.55), while adding lean body mass (Hedges' g = 0.30) compared with training alone [6]. In cognitive testing, a 2023 systematic review and meta-analysis of 8 randomised controlled trials showed an overall improvement in memory tasks (standardised mean difference = 0.29), with the largest benefits observed in older adults aged 66 to 76 years (standardised mean difference = 0.88), while younger adults showed no significant change [3]. In postmenopausal women, a 2026 meta-analysis of seven randomised trials (608 women, mean age about 62) found creatine raised leg-press strength by about 7.5 kg and lean mass by about 0.37 kg compared with placebo [7].

Doses used in studies

One 2009 study in rugby players used 25 grams a day for 7 days, then 5 grams a day for 14 days [4]. A 2025 study of 71 female football players used 20 grams a day for 7 days, then 5 grams a day for the rest of the season [8]. In postmenopausal women, benefits appeared at 5 grams a day or more with resistance training; 3 grams a day or less without training showed no measurable effect [7]. One brain trial gave 5 grams a day for six weeks [9]. A sleep-deprivation trial used a single dose of 0.2 g per kg of body weight [10].

Safety and interactions

In a 2026 structured review of 684 trials, side effects were infrequent and showed no consistent link to dose or duration [11]. Our searches did not find an official upper intake limit; the same review found no consistent rise in side effects even at high doses [11]. In a review of 29 studies with 951 women, total adverse events, gastrointestinal events and weight gain did not rise significantly [12]. Creatine raises blood creatinine slightly through normal metabolism, which the kidney review did not link to kidney damage [13]. Our searches found no study of creatine taken with NSAIDs or cyclosporine, so this summary cannot say whether they interact. The kidney review does not describe people with kidney disease, so ask a doctor before taking creatine if you have kidney disease [13]. The studies we searched did not cover pregnancy or breastfeeding, so this summary cannot say whether creatine is safe in those groups. In a secondary analysis of a large Parkinson's trial, caffeine was linked to faster progression only in people also taking creatine [14]. A 12-week trial of 38 men found no change in DHT or hair measures compared with placebo [15].

Caveats and open questions

Muscle creatine levels are usually somewhat lower in vegetarians than in omnivores [1]. Some supporting reviews, including a 2026 analysis of 684 trials, have authors with creatine-industry ties [11]. While memory benefits have been documented in older adults, cognitive findings in healthy young adults remain mixed and require larger confirmatory trials [3]. Some strength meta-analyses have authors with ties to creatine makers, including a 2024 review that declares industry research and donations [16]. The caffeine finding needs confirming in trials designed to test it [14]. Bone results conflict: a 2015 trial of 33 women who finished 12 months of training found less femoral neck bone loss with creatine [17], while two 2-year trials found no change in bone density [18][19]. In a 24-week trial of 60 vulnerable older women, creatine with training raised leg strength more than placebo alone, but not more than training with placebo [20].

References

  1. The role of dietary creatine.. Amino Acids, 2016.
  2. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis.. Front Nutr, 2024.
  3. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials.. Nutr Rev, 2023.
  4. Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players.. Clin J Sport Med, 2009.
  5. Creatine Supplementation and Lower Limb Strength Performance: A Systematic Review and Meta-Analyses.. Sports Med, 2015.
  6. Resistance training combined with creatine supplementation: a three-level meta-analysis of multidimensional outcomes from strength enhancement to body composition remodeling.. J Int Soc Sports Nutr, 2026.
  7. Creatine monohydrate for lean mass, strength, and bone density in postmenopausal women: a systematic review and meta-analysis.. J Int Soc Sports Nutr, 2026.
  8. Safety of long-term creatine supplementation in women's football players: a real-world in-season study.. J Int Soc Sports Nutr, 2025.
  9. The effects of creatine supplementation on cognitive performance-a randomised controlled study.. BMC Med, 2023.
  10. Single-Dose Creatine Reduces Sleep Deprivation-Induced Deterioration in Cognitive Performance.. Nutrients, 2026.
  11. Creatine Supplementation Dose and Duration Are Not Associated with Increased Side Effects: A Structured Review and Study-Level Dose-Response Analysis of Randomized Controlled Trials.. Sports (Basel), 2026.
  12. Risk of Adverse Outcomes in Females Taking Oral Creatine Monohydrate: A Systematic Review and Meta-Analysis.. Nutrients, 2020.
  13. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis.. BMC Nephrol, 2025.
  14. Caffeine and Progression of Parkinson Disease: A Deleterious Interaction With Creatine.. Clin Neuropharmacol, 2015.
  15. Does creatine cause hair loss? A 12-week randomized controlled trial.. J Int Soc Sports Nutr, 2025.
  16. Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis.. Nutrients, 2024.
  17. Effects of Creatine and Resistance Training on Bone Health in Postmenopausal Women.. Med Sci Sports Exerc, 2015.
  18. A 2-yr Randomized Controlled Trial on Creatine Supplementation during Exercise for Postmenopausal Bone Health.. Med Sci Sports Exerc, 2023.
  19. Creatine Supplementation (3 g/d) and Bone Health in Older Women: A 2-Year, Randomized, Placebo-Controlled Trial.. J Gerontol A Biol Sci Med Sci, 2020.
  20. Creatine supplementation and resistance training in vulnerable older women: a randomized double-blind placebo-controlled clinical trial.. Exp Gerontol, 2014.