What is GHK-Cu and where does it come from?

GHK-Cu is a tripeptide-copper complex (glycyl-L-histidyl-L-lysine plus a copper(II) ion, MW ~403.9 Da). Loren Pickart isolated it from human serum in 1973 after noticing that plasma from young donors stimulated repair processes in aged tissue more strongly than plasma from older donors. Endogenous plasma levels sit near 200 ng/mL in young adults and fall by roughly 60% with age.

Why is the GHK-Cu powder blue?

The cobalt-blue to violet color of the lyophilized powder comes from the bound copper(II) ion, not a dye or contaminant. It is a useful identity and quality marker: a correctly chelated GHK-Cu complex is colored, and the solution stays blue after reconstitution. A colorless powder labeled as GHK-Cu would be a red flag.

What concentration do researchers reconstitute GHK-Cu to?

Concentration is simply mass divided by solvent volume. A 100 mg GHK-Cu vial reconstituted in 2 mL of bacteriostatic water yields 50 mg/mL; the same vial in 5 mL gives 20 mg/mL. Topical research formulations are usually far more dilute (often well under 1%), while in-vitro work uses micromolar stock dilutions prepared from the reconstituted vial.

How does GHK-Cu differ from AHK-Cu?

Both are copper peptides. GHK-Cu is the broadly studied complex linked to genomic regulation, collagen synthesis and dermal remodeling. AHK-Cu (alanyl-histidyl-lysine copper) is a structural analog with reported affinity for hair-follicle dermal papilla cells and appears most often in trichology research rather than general skin work.

How is GHK-Cu stored?

The sealed lyophilized vial is best kept at -20 °C, where it is stable for around 18 months. Once reconstituted with bacteriostatic water, store the blue solution at 2–8 °C and use it within about 28 days. Protect both forms from direct light and moisture; copper complexes are light-sensitive.

GHK-Cu: The Copper Peptide in Skin, Hair & Repair Research

GHK-Cu (glycyl-L-histidyl-L-lysine bound to copper(II)) is a naturally occurring copper peptide first isolated from human plasma in 1973. In published research it is studied for collagen synthesis, skin remodeling and gene regulation across thousands of genes. It is supplied as a cobalt-blue lyophilized powder for research use only — not for human or animal use.

What the copper peptide GHK-Cu actually is

GHK-Cu is the best-characterized member of the copper peptide family. The molecule is a short chain of three amino acids — glycine, histidine and lysine — that chelates a single copper(II) ion. That copper is not incidental: it is the reactive core that lets the complex shuttle the metal to enzymes and signaling pathways inside the cell. Pickart first reported the activity in 1973, and four decades of biochemistry since then have made GHK-Cu one of the most studied bioactive peptides in dermatology and regenerative research.

A practical detail worth fixing early: GHK-Cu plasma levels are highest in young adults (around 200 ng/mL) and decline by up to ~60% with age. That correlation — falling copper peptide alongside slowing tissue repair — is what originally pointed researchers toward supplementing the molecule in in-vitro and topical models.

How GHK-Cu works: genes, collagen and copper transport

The defining finding came from genomics. A Broad Institute Connectivity Map analysis reported by Iorio et al. (Gene, 2010) found that GHK-Cu shifts the expression of more than 4,000 human genes, including a large fraction associated with aging. The pattern is not random: reparative and antioxidant genes are pushed up while several damage-associated genes are pushed down — what Pickart and Margolina (IJMS, 2018) describe as a partial reset toward a more youthful expression profile.

Downstream of that signaling, the reproducible cell-level effects are:

Up to +70% collagen type I and III synthesis in fibroblast cultures.
Angiogenesis driven through VEGF induction.
Anti-inflammatory action via NF-κB inhibition.
Antioxidant defense through superoxide dismutase (SOD) induction and reduced lipid peroxidation.
Stem-cell recruitment through integrin pathways.

Skin and hair research data

In a double-blind, placebo-controlled trial, Leyden et al. (Journal of Cosmetic Dermatology, 2018) reported measurable changes after 12 weeks of topical use: skin density up ~18%, elasticity up ~24%, and reduced wrinkle depth. More recent work by Hong et al. (Biogerontology, 2023) showed GHK-Cu delaying fibroblast senescence through the p16/Rb pathway — a mechanistic anchor under the cosmetic-endpoint data.

Hair research generally leans on the analog AHK-Cu, which has higher affinity for follicle dermal-papilla cells, but GHK-Cu itself appears in studies on follicle size and the perifollicular matrix. If hair is the research focus, both copper peptides are usually compared side by side — we break that comparison down, with topical vs in-vitro concentration practice, in copper peptides for hair & skin.

Reconstitution and concentration math

GHK-Cu ships as a cobalt-blue lyophilized powder — the color is the copper signature. Reconstitute it with bacteriostatic water; the solution should stay clearly blue. The only equation you need is concentration = mass ÷ volume.

Vial	Bacteriostatic water	Final concentration
100 mg	2 mL	50 mg/mL
100 mg	5 mL	20 mg/mL
200 mg	4 mL	50 mg/mL
300 mg	6 mL	50 mg/mL

For the full step-by-step on solvent choice, sterile technique and storage windows, see our bacteriostatic water & reconstitution guide. Lyophilized GHK-Cu keeps for ~18 months at -20 °C; reconstituted, use within ~28 days at 2–8 °C.

Sourcing research-grade GHK-Cu

Because the copper complex degrades under light and heat, identity and purity matter more than with simpler peptides. Look for >99% purity, a Certificate of Analysis from a named lab, mass-spec confirmation of the 403.9 Da complex, and — visually — the characteristic blue powder. For the wider checklist on purity standards and COA reading, the complete research peptides guide is the foundation reference.

For research use only. Not for human or animal use. Not a drug. The figures above describe published research findings and laboratory practice, and are not medical guidance.