GHK-Cu (Copper Peptide)
Naturally occurring copper-binding tripeptide (glycyl-histidyl-lysine) studied for skin remodeling, wound healing, and tissue-repair signaling.
Overview
GHK-Cu is a naturally occurring copper-binding tripeptide, glycyl-histidyl-lysine, first isolated from human plasma in the early 1970s and later identified in saliva, urine, and other body fluids. Plasma levels decline with age, which motivated research into its role in tissue remodeling and repair. In the research and cosmetic peptide markets it is usually supplied as a lyophilized complex of the tripeptide with a copper ion.
Mechanism
The GHK-Cu complex is proposed to act through several channels: it influences the expression of a broad set of genes related to extracellular-matrix turnover, stimulates synthesis of collagen, elastin, and glycosaminoglycans in skin fibroblasts, modulates matrix metalloproteinases and TGF-beta signaling, and delivers copper as a cofactor for enzymes such as superoxide dismutase. Antioxidant, anti-inflammatory, and cell-migration effects are also described in the literature.
Dosing
GHK-Cu is used topically in cosmetic research at low concentrations and by subcutaneous injection in some parenteral research protocols. Concentrations vary widely across cell-culture, topical, and injection studies, so figures must be taken from the primary literature; no approved systemic use exists.
Expected Effects
- skin-remodeling signals, including increased collagen and elastin production in fibroblast studies
- accelerated wound healing in several animal models
- improvements in skin firmness and appearance reported in cosmetic studies
- hair-follicle and dermal-papilla research, including mouse studies, suggesting effects on hair growth
Side Effects & Tolerability
Topical cosmetic use is generally well tolerated. Published safety data for injectable research use are limited; anecdotal reports mention nausea at higher doses and injection-site irritation. Copper overload is a theoretical concern with prolonged high-dose use but has not been characterized for this peptide. Because the tripeptide occurs naturally in human plasma at levels that decline with age, research discussion sometimes frames dosing around restoring youthful concentrations, although no therapeutic target has been defined.
Storage
Lyophilized GHK-Cu should be stored desiccated, protected from light, and kept frozen at -20 deg C or below. Reconstituted solutions should be refrigerated at 2-8 deg C and used within a short window, with repeated freeze-thaw cycles avoided.