Topic · Supplement
Creatine
Creatine is a compound the body makes and stores mostly in skeletal muscle, where it helps regenerate ATP during short, intense effort. Supplements are nearly always monohydrate. The best evidence is for added strength and lean mass when paired with resistance training. Findings on cognition, mood and blood sugar are smaller, more mixed or preliminary. Reviews describe it as safe in healthy adults, though people with kidney disease should ask a doctor first.
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Creatine FAQ
Does creatine actually build muscle?
Yes, with a caveat: it works alongside training. A 2025 meta-analysis of 69 studies found creatine plus resistance training improved bench press, squat strength and jump or sprint power, but not handgrip or leg press strength. A 2022 analysis found lean mass rose only when creatine was paired with resistance training, and the gain was significant in men but not in women.
Does it matter when you take creatine?
Probably not much. In an 8-week trial of 34 resistance-trained athletes, taking creatine before or after workouts made no difference on any outcome. A smaller 4-week trial showed a nonsignificant trend favoring after training, and a 2021 review called the evidence too thin for a firm conclusion. Taking it consistently, at a time you will remember, is the practical takeaway.
Is creatine safe for your kidneys?
In healthy people, the evidence is reassuring. A review of 19 studies covering 5 to 30 g a day for up to 5 years found no known harm to kidney function, and a 2017 position stand called creatine safe and well tolerated. Creatine can raise creatinine on blood tests, though. People with kidney disease were advised against use and should talk to a doctor first.
Does creatine cause hair loss?
The evidence is thin. One small trial in 20 male rugby players found blood DHT, a hormone tied to hair loss in susceptible people, rose after creatine loading. The trial never measured hair or scalp outcomes, and no larger trial has followed up. It is a hormone-marker finding, not a demonstrated hair-loss effect, though it may matter to people already worried about thinning.
Can creatine cause diarrhea or bloating?
Usually not from creatine alone, but large single doses can. In a 28-day trial of soccer players, a single 10 g dose caused diarrhea about twice as often as the same amount split into two 5 g doses, or as placebo. A heavier feeling in the first week is more often water: one trial found about 2% more total body water, not fat gain.