GHK-Cu

What it is

GHK-Cu is a copper-binding tripeptide — the sequence glycyl-L-histidyl-L-lysine complexed with a copper ion. The peptide GHK occurs naturally in human plasma, where its concentration falls with age, and it binds copper avidly. In the lab it stimulates collagen, elastin, and glycosaminoglycan production and shows a broad range of effects on skin-cell gene expression. It is unusual among the compounds on this site in that it has a genuine, decades-long track record as a cosmetic skincare ingredient (listed as copper tripeptide-1).

What it’s approved or studied for

It depends on how it is used. As a topical cosmetic, GHK-Cu is a widely used ingredient regulated as a cosmetic — it is meant to improve the appearance of skin, not to treat disease, and it carries no FDA drug approval. As an injected or systemic agent, GHK-Cu is not approved for any medical use and is sold as a research chemical; the “systemic anti-aging” and “regeneration” claims made for injectable versions are not backed by human trials.

What human evidence exists

For topical skin appearance, the evidence is Grade C (preliminary): several small controlled and comparative studies of GHK-Cu creams report modest but measurable improvements in fine lines, firmness, density, and texture over about 12 weeks. These are real human data, but the trials are small and short, and the effect sizes are generally smaller than those of established actives like retinoids. Wound-healing and hair-growth claims rest mostly on Grade D preclinical work. For injected/systemic use, the evidence is Grade U — there are essentially no controlled human trials.

The major unknowns

How much of the in-vitro and topical benefit translates into meaningful clinical outcomes; whether injected GHK-Cu does anything useful in humans; the pharmacokinetics and safety of systemic dosing; and the risk of copper overload with repeated injection are all unresolved. As with all research chemicals, injectable product purity and copper content are unregulated and uncertain.

Most important safety considerations

Topical cosmetic use is generally well tolerated, with occasional skin irritation or sensitivity. Injected or systemic GHK-Cu is a different matter: there is no established human safety profile, copper overload is a theoretical concern, and product quality is uncontrolled. Do not treat a cosmetic-ingredient safety record as evidence for injectable use. This page summarizes the research record; it is not medical advice or an endorsement of use.