What It Is
GHK-Cu is the copper-bound form of GHK, a naturally occurring tripeptide made of glycine, histidine, and lysine. It is detectable in human plasma, saliva, and urine, and its concentration is reported to decline with age, which partly explains the research interest in skin and tissue repair.[1] In the literature it also appears as Cu-GHK, GHK copper, copper tripeptide, and prezatide copper.
GHK-Cu is studied mainly in dermatology and wound-healing research, with a smaller and less certain body of work on hair follicles. It is not a single approved drug -- it shows up in cosmetic products, compounded preparations, and a handful of registered clinical studies, each with its own evidence and regulatory picture.
How It Works
GHK's affinity for copper ions is central to its proposed activity. Copper participates in enzymes involved in connective-tissue formation and antioxidant defense, and GHK-Cu is studied as a way copper may be coordinated or delivered at the tissue level.[10] Laboratory studies report that GHK-Cu stimulates collagen synthesis in fibroblast cultures and influences matrix metalloproteinases and their tissue inhibitors -- enzymes involved in remodeling the extracellular matrix, the structural scaffold that supports skin and connective tissue.[4][5]
These are cell-level mechanisms that make GHK-Cu biologically plausible for skin and wound repair. They do not, by themselves, prove that any particular cream, gel, or injection produces a specific cosmetic or medical outcome in a person.
What the Research Shows
The most substantive human evidence for GHK-Cu is topical. A review of controlled studies described Cu-GHK creams and eye creams associated with improvements in skin density, thickness, elasticity, and wrinkle appearance over 12-week periods in small groups of women.[2] One older, small study of 20 women reported new collagen production in 70% of those using a Cu-GHK product after one month, versus 50% for vitamin C and 40% for retinoic acid -- a notable but dated comparison never broadly replicated.[2]
The strongest clinical signal comes from a randomized, placebo-controlled diabetic-ulcer trial, where topical glycyl-L-histidyl-L-lysine copper gel was associated with 98.5% ulcer closure versus 60.8% for vehicle, plus a lower infection rate, within a standardized wound-care protocol.[3] Hair-growth evidence is weaker, resting mainly on a 1991 mouse study and an in-vitro human follicle model rather than clinical trials in people with hair loss.[6][13] Injectable and whole-body anti-aging claims have essentially no comparable human evidence.
Safety & Side Effects
Safety considerations differ sharply by route. Topical GHK-Cu products can cause irritation, dermatitis, or allergic reactions, especially when layered with acids, retinoids, or other active skincare ingredients; a registered topical wound-healing trial specifically excludes participants with known copper, peptide, or excipient sensitivity.[7]
Injectable GHK-Cu is a different matter. FDA compounding-risk materials identify injectable GHK-Cu as a potential immunogenicity concern, citing aggregation, peptide-related impurities, and limited human safety data to inform risk.[8] Copper itself is essential to normal physiology, but that does not mean any copper-peptide exposure is automatically harmless, particularly if a formulation changes how much copper reaches systemic circulation.
Regulatory Status
No FDA-approved prescribing label establishes GHK-Cu as a drug for any medical indication. Cosmetic GHK-Cu products are regulated as cosmetics, meaning they generally do not require FDA premarket approval aside from color additives, though manufacturers remain responsible for safety and accurate labeling.[11]
Compounded GHK-Cu sits in a separate category. FDA's May 2026 bulk-substances review listed GHK-Cu for non-injectable routes as a substance under evaluation for the 503A compounding bulks list, with a Pharmacy Compounding Advisory Committee consultation expected before the end of February 2027.[19] Injectable-route GHK-Cu, by contrast, is flagged as a safety concern rather than sitting on a similar evaluation track.[8] Neither status amounts to FDA approval of GHK-Cu as a drug.