GHK-Cu

GHK-Cu is a tripeptide that occurs naturally in human plasma and binds copper. Plasma levels decline with age, which is the observation much of the interest in it rests on.

Its strongest evidence is topical and cosmetic: studies of skin appearance, collagen and wound healing, where it has been used in commercial formulations for years. That evidence does not transfer to systemic administration, which is far less studied and raises separate questions given the compound's role in copper transport. The distinction between topical and injected use is the most important one on this page.

Collagen synthesis, skin appearance and wound repair, mostly in topical application. Systemic administration is comparatively unstudied.

Topical use is generally reported as well tolerated. Systemic administration raises questions about copper balance that the published literature does not answer.

Supplied as a blue-tinted powder, the colour coming from the bound copper. Formulated both topically and as a lyophilised powder for reconstitution.