GHK-Cu

Isolated from human blood plasma by Loren Pickart in 1973. Natural levels fall from about 200 ng/mL at age 20 to about 80 ng/mL by age 60. It has been used in cosmetic skin products for decades.

GHK binds copper tightly and is thought to deliver it to enzymes such as lysyl oxidase, which cross-links collagen and elastin. Cell and animal work links it to collagen synthesis, antioxidant activity and tissue remodeling. Claims that it 'resets' thousands of genes come from computer analysis of cell-culture data, not human outcomes.

Small topical studies report improved skin density, thickness, firmness and wrinkles, but many were industry-run or published only as abstracts. A large phase III wound program (Iamin gel, 511 people with diabetic foot ulcers) reportedly did no better than placebo in 1994. Hair research is thin and mostly uses combination products. Animal studies show faster wound closure and less lung inflammation. No human data exist for non-topical forms, and human pharmacokinetics are unknown.

Topical studies report good tolerance, though formal side-effect data are largely unpublished. FDA flags a possible immune-reaction risk for injectable GHK-Cu. Clinicians reported site infections and raised liver enzymes and copper levels in some people using non-topical products outside studies, cause unconfirmed.

Not FDA-approved as a drug; copper tripeptide-1 is legal in cosmetics with appearance-only claims. The topical form is in FDA's 503A Category 1 (under evaluation) as of May 2026; the injectable form was removed from Category 2 in April 2026 but has no compounding pathway. It is reportedly scheduled for FDA advisory committee review by early 2027. Not named on the WADA list but could fall under S0. Status as of October 2026.