Tested athletes need NSF Certified for Sport options to avoid contamination risk. The brands below are gold-standard for tested athletes.

Selection criteria. NSF Certified for Sport; third-party batch testing.

This guide ranks our top picks, explains the methodology, and gives you a clear protocol for getting started.

Creatine is a naturally occurring compound synthesized in the liver, kidneys, and pancreas from arginine, glycine, and methionine. About 95% of body creatine resides in skeletal muscle, with the remainder in brain, heart, and other high-energy tissues. Dietary creatine comes primarily from red meat and fish (~1 g/day in omnivores; near-zero in vegans).

Inside cells, creatine is phosphorylated to phosphocreatine (PCr), which serves as a rapid ATP-regeneration system. During short, high-intensity efforts (1–10 seconds), the ATP–PCr system is the dominant energy supplier. Creatine supplementation increases muscle PCr stores by 10–40%, improving repeat-effort performance, strength, and lean mass gains over weeks of consistent training.