Category: metabolite
Aliases: Methyl-guanidinoacetic acid, Creatine, Cr, creatine-monohydrate, creatine
Endogenous guanidinoacetate derivative synthesised from [[arginine]] + [[glycine]] + [[methionine]] (via SAMe methyl transfer). Stored in skeletal muscle + brain via the [[creatine_phosphocreatine_energy]] system primarily as phosphocreatine (PCr). Creatine kinase catalyses PCr + ADP ↔ creatine + ATP — the phosphate shuttle that buffers ATP during high-turnover activity (5–10 s maximal efforts; brain cognitive load under sleep deprivation or hypoxia). Most extensively researched ergogenic agent; decades of consistent safety data across many populations including pediatric.
PO: 3h