GHK-Cu

GHK-Cu is the tripeptide glycyl-L-histidyl-L-lysine bound to a copper(II) ion. It was first isolated from human plasma in 1973 by Loren Pickart and has been the subject of over 200 peer-reviewed papers on skin remodeling, wound healing, and transcriptional gene modulation.

Topical GHK-Cu is regulated as a cosmetic ingredient (no FDA premarket approval required for cosmetics). Injectable formulations are not FDA-approved for any human indication and are supplied as research-grade chemical reference compounds.

Topical evidence for skin improvement is strong at the mechanism level (collagen, elastin, GAG synthesis upregulation in fibroblasts) and moderate at the human cosmetic-trial level (Leyden 2002 conference abstract; Finkley 2005 book chapter). Most published topical work uses 0.01–0.1% formulations.

Mechanism-level data show GHK-Cu enlarges hair follicles and prolongs the anagen phase in rodent models. Human hair-loss clinical evidence is anecdotal; no completed Phase 3 trials with GHK-Cu as the primary intervention.

Free GHK is the uncomplexed tripeptide. GHK-Cu is GHK bound to a Cu²⁺ ion in a 1:1 complex. The copper-bound form is the biologically active species in most in-vitro readouts and is what circulates in human plasma.

Pickart's reviews quote a decline from roughly 200 µg/L at age 20 to roughly 80 µg/L at age 60. This is a summary of historical published assays, not from a single prospective cohort. The decline is hypothesized to contribute to age-related tissue-repair slowdown.

14 days at 2–8 °C protected from light. Copper-peptide complexes degrade faster than non-copper peptides in solution due to redox activity. The lyophilized cake is stable for 24+ months at 4 °C.

GHK-Cu is supplied as a research-grade injectable reference compound. Community-reported research protocols (1–2 mg, 2–3× per week subcutaneously) are not validated by published clinical trials and are not recommendations from this wiki.

GHK-Cu is not currently on the WADA Prohibited List as of the 2026 publication.

The complex is C14H24CuN6O4 (glycyl-L-histidyl-L-lysine + one Cu²⁺ ion in a square-planar coordination).

The Cu²⁺ ion in the GHK-Cu complex has a characteristic d-d electronic absorption in the visible spectrum, producing the iconic cobalt-blue color of reconstituted GHK-Cu and the pale-blue lyophilized cake.

Topical co-formulation is common in cosmetic products. Co-application can potentiate skin barrier disruption and irritation in sensitive users; alternating evenings rather than simultaneous application is the common approach.

Pickart's transcriptomic study (Vasquez-Soltero et al. 2015) reported modulation of multiple thousand genes in dermal fibroblasts at the dose tested. The 4,000-gene figure widely cited online comes from that specific in-vitro readout; magnitude varies by cell type, dose, and exposure window.

Many over-the-counter 'copper peptide' products contain GHK-Cu or related copper-tripeptides at lower percentages. Research-grade GHK-Cu sold as lyophilized powder is the same molecule supplied at known purity for laboratory reconstitution to any desired concentration.

Not studied in pregnancy or lactation. Research-grade GHK-Cu is supplied for in-vitro use only; no human dose is recommended.