Strong evidence

Creatine monohydrate is effective for increasing muscle mass and strength alongside training, and is safe in healthy people at recommended doses.

In practice

One of very few supplements with a genuine evidence base. Monohydrate is the studied form; the expensive variants have nothing extra behind them.

What it doesn't say

The position stand is from a body with industry links, which is worth knowing — though the underlying literature on monohydrate is large and consistent. Anyone with kidney disease should ask a doctor first.

Source

• Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, Candow DG, Kleiner SM, Almada AL, Lopez HL (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14:18. doi.org/10.1186/s12970-017-0173-z