Creatine: The Best-Supported Supplement for Muscle Strength
Creatine monohydrate is one of the most studied sports supplements, and its benefit for strength during resistance training is well established.1 The evidence for older adults, memory and long-term safety is newer; here is what the studies show and where they are still thin.
- Creatine is stored in muscle, largely as phosphocreatine, an instant energy reserve; in a classic study, 20 g a day for five days raised muscle creatine by about 25% in five of eight people, while three barely responded.2
- In a meta-analysis of 22 trials in older adults, creatine taken during resistance training added 1.37 kg more lean mass than training alone, with greater chest press and leg press strength.6
- For the brain, a 2018 review of six trials found creatine may improve short-term memory and reasoning in healthy people, with no change in young people and conflicting results for other mental skills.4
- A 2017 position stand concluded that taking up to 30 g a day for up to five years has been safe and well tolerated in healthy people, and a 12-week trial in type 2 diabetes found no effect on measured kidney function.7,5
- The same position stand suggests that habitual intake of around 3 g a day throughout life may provide health benefits.7
Creatine's effect on strength during resistance training is well documented. A review of 22 studies found that strength rose by an average of 20% with creatine versus 12% with placebo during resistance training, and weightlifting performance by 26% versus 12%.1 Newer research has looked at older adults, memory and safety, with more mixed results.
Creatine Biochemistry
Creatine is made in the body and stored mostly in skeletal muscle, largely as phosphocreatine (PCr), which rapidly regenerates ATP during short bursts of intense effort. In a 1994 study, taking 20 g a day for five days raised total muscle creatine by about 25% in five of eight people and sped up PCr resynthesis after intense contractions by about 35%; the other three had little change in muscle creatine and no faster PCr resynthesis.2
Diet supplies creatine mainly through meat and fish, so vegetarians take in little. In the memory trials, vegetarians responded better than meat-eaters.4
Resistance Training and Sarcopenia Prevention
In older adults, creatine has mostly been studied alongside resistance training. A 2017 meta-analysis of 22 randomized trials with 721 participants (mean ages 57 to 70) found that creatine during training increased lean tissue mass by 1.37 kg more than placebo and improved chest press and leg press strength.6 An earlier set of meta-analyses also found benefits for muscle mass and upper-body strength, and early promise for bone density.3
How creatine produces these gains is not settled: the meta-analysis authors noted that the possible mechanisms have yet to be evaluated extensively.6
Cognitive Effects: The Emerging Evidence
Creatine is also an essential brain compound, and some researchers hypothesize that it aids thinking by improving energy supply and protecting nerve cells.4
The evidence so far is limited. A 2018 systematic review found six randomized trials with 281 healthy people: short-term memory and intelligence or reasoning may improve, but results for other areas, including long-term memory, attention, executive function, reaction time and mental fatigue, were conflicting, and performance did not change in young people. The authors saw potential benefit for older and stressed individuals and called for larger studies.4
Safety
The International Society of Sports Nutrition's 2017 position stand concluded that short- and long-term creatine supplementation, up to 30 g a day for five years, is safe and well tolerated in healthy individuals and in a range of patient groups from infants to older adults.7 Kidney safety is a common worry: in a 12-week randomized trial in people with type 2 diabetes doing exercise training, creatine did not change measured kidney filtration, creatinine clearance, urea, electrolytes, proteinuria or albuminuria.5 People with kidney disease should talk to a clinician before taking it.
Put this research into practice: Supplement Evidence Database · Supplement Interaction Checker
References
- 1Rawson ES, Volek JS. "Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance." J Strength Cond Res. 2003;17(4):822-31. PubMed · DOI
- 2Greenhaff PL, et al. "Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis." Am J Physiol. 1994;266(5 Pt 1):E725-30. PubMed · DOI
- 3Candow DG, et al. "Creatine supplementation and aging musculoskeletal health." Endocrine. 2014;45(3):354-61. PubMed · DOI
- 4Avgerinos KI, et al. "Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of randomized controlled trials." Exp Gerontol. 2018;108:166-173. PubMed · DOI
- 5Gualano B, et al. "Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial." Eur J Appl Physiol. 2011;111(5):749-56. PubMed · DOI
- 6Chilibeck PD, et al. "Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis." Open Access J Sports Med. 2017;8:213-226. PubMed · DOI
- 7Kreider RB, et al. "International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine." J Int Soc Sports Nutr. 2017;14:18. PubMed · DOI
