What Is GHK-Cu?
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK), a small copper-binding peptide that occurs naturally in human plasma and declines with age. It is best known as a cosmetic ingredient, where it is used topically for skin firmness, wound repair and hair support. Of the peptides in this batch it has the most developed evidence base, though the strongest data are mechanistic and cosmetic rather than large clinical trials.
Evidence
GHK-Cu has been shown in in vitro and animal work to stimulate collagen, elastin and glycosaminoglycan synthesis, modulate matrix metalloproteinases, and promote angiogenesis and tissue remodeling; a 2018 review catalogues these regenerative and gene-modulating actions across skin, nerve and connective tissue 1Reference 1ReviewRegenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data — reviewView study →. A topical copper tripeptide complex accelerated wound healing in an irradiated rat model 2Reference 2AnimalEffects of topical copper tripeptide complex on wound healing in an irradiated rat model — rat/in vivo. https://pubmed.ncbi.nlm.nih.gov/23744835/View study →. Much of the human evidence comes from cosmetic testing of copper-peptide creams rather than controlled clinical trials, and I did not find a large randomised human trial of GHK-Cu in this quick pass; treat firmer efficacy claims (anti-aging, hair regrowth) as commonly marketed but not yet established by strong human data.
Dosage & Safety
There is no established supplement dose. In cosmetics GHK-Cu is typically formulated in creams and serums at low percentages; a personal dosing recommendation is out of scope here. GHK is naturally occurring and reportedly nontoxic at the nanomolar concentrations at which it is active 1Reference 1ReviewRegenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data — reviewView study →, and topical use has a long cosmetic safety record. Injectable/systemic GHK-Cu sold as a “research peptide” has not been characterised for safety in humans, is not an approved dietary supplement or drug, and copper overload is a theoretical concern with systemic dosing. Interactions, pregnancy safety and long-term systemic effects are not established. This is informational only.
References
- Pickart L, Margolina A (2018). Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data — review. Int J Mol Sci. https://pubmed.ncbi.nlm.nih.gov/29986520/
- Kim Y-J et al. (2013). Effects of topical copper tripeptide complex on wound healing in an irradiated rat model — rat/in vivo. https://pubmed.ncbi.nlm.nih.gov/23744835/