What GHK-Cu is, and what happened at twelve weeks in the study everyone cites at six
In short
GHK-Cu is a human tripeptide bound to copper, naturally present in plasma and described as an activator of tissue remodelling. Its literature is preclinical: human fibroblasts in culture and rat models. In the knee study, the effect was transient and had disappeared by twelve weeks.
GHK is a human tripeptide — glycine, histidine and lysine — naturally present in plasma, whose concentration falls with age. It binds copper with high affinity, and that complex, GHK-Cu, is the form in which it is studied and sold [1].
It is described as an activator of tissue remodelling, with effects on extracellular matrix, fibroblasts and antioxidant response [1][2].
What has been measured, and in what
All the evidence located is preclinical: cell culture and animal models.
- Human fibroblasts in culture. One study measured the effect of the tripeptide and its copper complex on TGF-β secretion in normal human dermal fibroblasts [4]. That is culture, not a person's skin.
- Wound healing in irradiated rats. The complex was studied applied topically on healing in an irradiated rat model [3].
- Rat knee, and the detail that changes everything. Seventy-two rats with anterior cruciate ligament reconstruction were randomly assigned to saline or two concentrations of the complex. At six weeks, the treated groups showed a smaller side-to-side laxity difference than control, and one of them higher graft stiffness. At twelve weeks, those differences were no longer significant [5].
That last point deserves reading twice, because it is the difference between speeding something up and improving it. The authors put it in the title of the paper: the effect was transient. Any page citing the six-week result without mentioning the twelve-week one is telling half a study.
What there is not
No randomised clinical trial of the complex in people has been located, nor any approved indication. The compound is widely used in cosmetics, where the regulatory bar is different: there, clinical efficacy does not have to be demonstrated the way it is demanded of a medicine.
Much of the recent research is also devoted to how to deliver it — liposomal vehicles and other delivery systems — which indicates that stability and penetration are part of the problem rather than a settled detail.
This page describes published literature. It is not medical information, it does not describe a therapeutic use, and it does not replace any healthcare professional.
What to look at when comparing suppliers
- That it is the copper complex and not the bare tripeptide: they are two different things and the cited studies use the complex.
- HPLC purity for the batch and identity confirmation, with a readable certificate.
- Colour and appearance of the lyophilisate. The copper complex has a characteristic colour; a vial without it deserves a question before a purchase.
References
- [1] Pickart L. (2008). The human tri-peptide GHK and tissue remodeling. J Biomater Sci Polym Ed. PMID 18644225 View source
- [2] Pickart L. et al. (2012). The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging. Oxid Med Cell Longev. PMID 22666519 View source
- [3] Parker N.P. et al. (2013). Effects of topical copper tripeptide complex on wound healing in an irradiated rat model. Otolaryngol Head Neck Surg. PMID 23744835 View source
- [4] Gruchlik A. et al. (2014). Effect of GLY-HIS-LYS and its copper complex on TGF-β secretion in normal human dermal fibroblasts. Acta Pol Pharm. PMID 25745767 View source
- [5] Fu S.C. et al. (2015). Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction. J Orthop Res. PMID 25731775 View source
This page reports what has been published in the scientific literature about a research molecule. It is not medical information, it does not describe a therapeutic use, and it does not replace any healthcare professional. The product is sold strictly for in vitro research.
