Creatine Monohydrate

Category: metabolite

Aliases: Methyl-guanidinoacetic acid, Creatine, Cr, creatine-monohydrate, creatine

Pharmacological Mechanism

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.

Half-Life (t½)

PO: 3h

Dosing Guidelines

• PO: Typical 3.67 g (Range: 3–5 g)

Target Organ Systems

• musculoskeletal

Interactions

• TMG (Betaine) (synergistic): Methionine → SAMe → creatine biosynthesis consumes methyl donors; TMG replenishes. Commonly stacked with creatine + NMN / NAD+ precursors.
• Methionine (synergistic): Methyl donor for endogenous creatine biosynthesis.

Pathways It Modulates

• Creatine / phosphocreatine energy buffer (substrate) — PCr pool (skeletal muscle + CNS)
• Creatine SLC6A8 intracellular osmotic loading (substrate) — SLC6A8 (CRT1) → intramuscular creatine pool

Chemical Identifiers

• PubChem CID: 80116
• Formula: C4H11N3O3
• Molecular weight: 131.13 g/mol
• InChIKey: MEJYXFHCRXAUIL-UHFFFAOYSA-N
• SMILES: CN(CC(=O)O)C(=N)N.O

References

• PMID 28615996
• PMID 12520625