A naturally occurring copper-binding tripeptide found in blood plasma, studied mostly for skin and hair; its human evidence is largely topical and cosmetic.
Reviewed for accuracy · Last reviewed July 7, 2026GHK-Cu is a small tripeptide (glycyl-L-histidyl-L-lysine) bound to a copper ion. It occurs naturally in human plasma and declines with age, and it's studied mostly for skin (collagen production and wound healing) and for hair. Most of the human data comes from topical and cosmetic use, where it appears in a number of skincare products.
Injectable GHK-Cu, by contrast, is largely community-driven and has very little clinical dosing literature behind it, so any numbers circulated for injection should be treated as anecdotal rather than established. One thing worth knowing: reconstituted GHK-Cu turns a deep blue, and that color comes from the copper and is normal, not a sign the peptide has gone bad.
Human dosing evidence is essentially topical: cosmetic serums and creams use roughly 1 – 3%. Injectable figures (often 1 – 2 mg daily) are community-cited only, with no clinical dosing literature behind them.
Read the full GHK-Cu dosage guide →There is very little human safety data for injected GHK-Cu. Reported effects are mostly local, such as injection-site irritation and a temporary blue tint from the copper. The blue color is expected, not a warning sign.
Read the full GHK-Cu side effects guide →Keep unmixed vials refrigerated and away from light. Once reconstituted, most research reports store it refrigerated for roughly 4 weeks. See the full storage & safety guide for handling and disposal basics.
This page is an independent educational reference and is not medical advice. Talk to a doctor before starting any compound.