Creatine

For adults who perform hard, brief efforts, creatine monohydrate is one of the better-supported sports supplements. Recent evidence syntheses report greater post-intervention strength than placebo, and the clearest pattern is that creatine works best as an addition to a structured training program rather than as a substitute for training.

Power is also a reasonable target, particularly repeated sprinting or short anaerobic tests. The effect is not universal across every sport or outcome, however, and a benefit in a high-intensity test should not be interpreted as better endurance running or better overall athletic performance.[4][7][5][2]

Creatine is made naturally in the body and is also found in foods such as red meat and seafood. Most of the body’s creatine is stored in skeletal muscle, where it exists partly as phosphocreatine.

During a short, intense effort, phosphocreatine helps rapidly rebuild ATP, the molecule cells use as immediate energy. Supplementation can raise muscle creatine stores, which gives the muscle more capacity for repeated high-power contractions. That mechanism makes the performance findings plausible, but a plausible mechanism alone cannot prove that a supplement improves a meaningful outcome in every adult.[1][7]

A 2025 meta-analysis covering adults with different training backgrounds found that strength improved more after creatine than after control supplementation, although the size of the effect varied. An older review of 22 studies likewise reported larger average strength and weightlifting gains when creatine was paired with resistance training, while noting wide variation between studies.

In a synthesis limited to healthy men aged 18 to 30, creatine plus resistance training was associated with pooled increases of about 3.39 kilograms in fat-free mass and 2.70 kilograms in lean body mass. Those gains were not significant in non-resistance-training conditions. The same review found higher Wingate peak and mean power, but the jump-test estimate was highly inconsistent between studies. In postmenopausal women, another review found a smaller pooled lean-mass difference of 0.37 kilograms and a leg-press strength difference of 7.5 kilograms; its prediction interval for lean mass included no effect, and most studies had some risk-of-bias concerns.[4][3]

Creatine may help someone tolerate repeated hard efforts, but that is not the same as faster recovery from muscle damage, soreness, or injury. In a network meta-analysis of trained athletes, creatine ranked best for strength, whereas omega-3 supplementation ranked best for recovery outcomes. Because network meta-analyses combine direct and indirect comparisons, these rankings are not a replacement for a large head-to-head recovery trial.

The cognitive evidence is earlier. One randomized study included only 29 healthy adults undergoing 21 hours of sleep deprivation and found that a single creatine dose reduced deterioration on several attention, language, logic, and numerical tasks. That result suggests a possible benefit when the brain is under acute energetic stress, not proof of routine cognitive enhancement in rested adults. A separate registered trial in older adults measured cognition during resistance training, but its reported improvements largely occurred with training and did not provide a clean, easily interpreted creatine-versus-placebo cognitive effect.[5][1]

In the postmenopausal-women evidence synthesis, adverse events were mild and occurred at similar rates with creatine and placebo, while measured renal indices were unchanged. A sports-nutrition position stand also reported good tolerance in healthy people in studies lasting up to five years, including studies using higher daily intakes. This is reassuring evidence, not a guarantee of zero side effects or unlimited long-term safety.

The safety evidence mainly concerns studied creatine monohydrate protocols in defined groups. It does not prove that every multi-ingredient product has the same contents, quality, or evidence. For example, a trial in older men with type 2 diabetes found strength-related effects from protein supplementation with resistance training, with or without a synbiotic; it did not test creatine. That result cannot be used as proof for a creatine product. People with kidney disease, abnormal kidney tests, or medicines that affect kidney function need individualized medical advice rather than assuming that results in healthy volunteers apply to them.[9][1]