What is creatine?

Its biological role

Creatine is synthesized from the amino acids glycine, arginine, and methionine in the liver and kidneys. Inside the muscle cell it is converted to phosphocreatine, which speeds up the regeneration of ATP — the body's universal energy currency — during short, intense efforts (Kreider et al., 2017).

What it does as a supplement

A daily intake of 3 to 5 grams of creatine monohydrate increases intramuscular creatine stores (Kreider et al., 2017). Under EU Regulation 432/2012, creatine carries an approved health claim: a daily intake of at least 3 grams increases physical performance in successive bursts of short-term, high-intensity exercise. A meta-analysis covering 60 randomized controlled trials (n = 1,297) found a statistically significant, small-to-moderate effect on lower-limb maximal strength (Cohen's d 0.24–0.34) (Lanhers et al., 2015). Its effect on hypertrophy is indirect — it comes from training at a higher quality.

Natural sources

Creatine occurs naturally in meat and fish — roughly 3 to 5 grams per kilogram of raw beef or pork. Vegetarians and vegans accordingly take in less creatine through their diet (Antonio et al., 2021).