What Is GHK-Cu and How Does It Work
GHK-Cu is the copper(II)-bound complex of GHK, a naturally occurring tripeptide (glycyl-L-histidyl-L-lysine) first identified in human plasma in the 1970s. GHK is also detectable in saliva and urine, and its circulating concentration declines steadily with age - a pattern of interest given the compound's proposed role in tissue maintenance and repair. GHK has a strong, specific affinity for copper, and its copper-bound form is the biologically active species studied in most research.
GHK-Cu's proposed mechanisms are broad rather than singular: it acts as a chemoattractant for repair cells such as macrophages and mast cells, has anti-inflammatory effects by suppressing free radicals and inflammatory mediators, and increases protein synthesis of collagen, elastin, matrix metalloproteinases, and various growth factors. Its copper-binding structure is also thought to assist in regulated copper transport into and out of cells, a process tied to angiogenesis and enzymatic antioxidant activity. Together, these actions are the basis for its study in skin, wound, and connective-tissue remodeling contexts.
Research Dosing
Dosing depends heavily on route, and the two routes are not interchangeable in terms of evidence or regulatory status. Figures below are commonly cited ranges, not a clinically validated protocol.
| Form | Dose | Frequency | Route |
|---|---|---|---|
| Topical (copper tripeptide-1) | ~1–2% concentration | Once or twice daily | Topical serum/cream |
| Injectable (research chemical) | ~1–2mg/day (commonly cited, unvalidated) | Once daily | SubQ injection |
Context: Topical GHK-Cu has by far the largest base of use and published cosmetic-science literature. Injectable/subcutaneous use is a separate, far less studied application discussed mainly in research-community protocols, without the same regulatory footing as the topical cosmetic form.
Regulatory Status
GHK-Cu has never been approved by the FDA as a therapeutic drug for any medical indication. However, its regulatory picture is more layered than most research peptides because of its dual use: as "copper tripeptide-1," topical GHK-Cu is a recognized cosmetic ingredient, and the FDA does not require premarket approval for cosmetic ingredients marketed with appearance-related (not disease-treatment) claims - this is why it appears in numerous over-the-counter serums and creams without issue. Injectable or subcutaneous GHK-Cu sits in a different category entirely: it is not FDA-approved, is not sold as a cosmetic, and is marketed strictly as a research chemical for laboratory use, not human consumption. GHK-Cu is not currently on the FDA's 503A bulk drug substances list and is slated for a future FDA Pharmacy Compounding Advisory Committee review as of this writing, with no final compounding determination yet issued. Consult a qualified healthcare provider before considering any injectable research compound protocol.
What Research Shows
GHK-Cu has one of the longer and more diverse research records among compounds in this category, spanning cell-culture, animal wound-healing, and topical cosmetic studies over several decades. A widely cited review by peptide researcher Loren Pickart summarizes GHK-Cu's activation of tissue remodeling pathways: stimulation of collagen, elastin, and glycosaminoglycan synthesis, chemoattraction of immune and repair cells, antioxidant and anti-inflammatory activity, and accelerated wound healing observed across skin, gastrointestinal, and boney tissue in animal models. Much of the strongest mechanistic and efficacy evidence comes from cell-culture and animal studies rather than large randomized human trials, though decades of use in topical cosmetic formulations provide a substantial real-world safety track record for that specific application.
For a broader look at how skin- and repair-focused peptides fit into a research protocol, see the peptides and anti-aging guide.