GHK-Cu
Tissue repair / cosmetic peptide
Also known as: Copper tripeptide-1, Copper peptide, Prezatide copper acetate
Evidence is limited to animal or in-vitro work. No human pharmacokinetics. Any human dose in circulation is extrapolated, and extrapolation across species routinely fails.
No published human pharmacokinetic half-life located for GHK or GHK-Cu by any route. GHK occurs endogenously in human plasma and declines with age, but a systemic half-life for exogenously administered GHK-Cu was not found. Molecular weight is left blank rather than computed from the formula, since the copper complex differs from the free peptide.
No systemic human dose established. GHK-Cu is used almost exclusively TOPICALLY, where concentration (% w/w), not a per-administration mcg dose, is the relevant unit, the mcg model does not apply. Injectable GHK-Cu has no published human dosing.
Topical cosmetic use is generally well tolerated; irritation and contact sensitivity are the main reported issues. The efficacy evidence base is largely in vitro, rat wound models, and cosmetic-industry studies rather than rigorous clinical trials. SYSTEMIC OR INJECTED use carries an unquantified risk of copper overload, copper is redox-active with real hepatic and neurologic toxicity in excess, and no human data define a safe injected dose. Injectable GHK-Cu should not be treated as an established practice.