GHK-Cu

A naturally occurring copper-binding tripeptide, glycyl-L-histidyl-L-lysine complexed with copper(II), studied for collagen synthesis, tissue remodelling, wound repair and broad modulation of the human transcriptome.

What it is

GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (sequence Gly-His-Lys), formed when the peptide binds a single copper ion in a 1:1 stoichiometry. The peptide was first isolated from human plasma by Loren Pickart in the 1970s, where it was identified as a factor that helped older liver tissue behave more like younger tissue in culture. It is classed as a copper-binding matrikine, a small signalling peptide that carries and delivers copper to cells and influences the extracellular matrix.

The molecule occurs naturally in blood, saliva and urine. Its plasma concentration is age-dependent: it averages around 200 ng/mL at age 20 and falls to roughly 80 ng/mL by age 60, a decline that has made it a recurring subject in regeneration, skin-biology and ageing research (Dou et al., 2020). Supplied strictly for laboratory research use only, not for human or veterinary use.

How it works

GHK has a very high affinity for copper(II) and can carry copper between compartments, delivering it to cells and enzymes that require it. Through this copper-shuttling and direct signalling, GHK-Cu is studied as a stimulator of collagen, elastin and glycosaminoglycan synthesis in dermal fibroblasts, and as a regulator of the matrix-remodelling balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). In fibroblast and ex-vivo skin work it raised expression of both MMP-1/MMP-2 and TIMP-1, shifting the TIMP-to-MMP ratio toward net collagen and elastin accumulation (J Aging Sci).

Beyond the matrix, gene-expression profiling using the Broad Institute Connectivity Map indicates GHK acts as a broad transcriptional modulator. It has been reported to change the expression of a large fraction of human genes, resetting an age-shifted expression pattern toward a healthier profile, and to engage antioxidant (Nrf2), DNA-repair, ubiquitin-proteasome and anti-inflammatory (reduced NF-kB and TNF-alpha) pathways (Pickart & Margolina, 2018). At low nanomolar concentration it also raised vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in dermal fibroblasts, consistent with a role in angiogenesis during repair.

What the research shows

The GHK-Cu literature spans classic in-vitro and in-vivo collagen work by Pickart and Maquart, controlled topical studies on photoaged skin, and modern transcriptomic analyses by Pickart and Margolina. The headline quantitative findings below are drawn from peer-reviewed sources; every figure carries its source link. Because most controlled human work has used topical formulations, injectable and systemic outcomes remain a research question rather than an established result.

Side Effects

Almost all human safety data for GHK-Cu comes from topical and cosmetic dermatology, where it is generally well tolerated, with reactions usually limited to mild, transient redness or irritation at the application site. Reviews by Pickart and colleagues describe decades of cosmetic and wound-care use without reported adverse effects, and the peptide is active at very low nanomolar concentrations. It is important to note that GHK-Cu is a copper-carrying peptide, and there are no controlled human safety trials for injected or otherwise systemic use. Effects reported below come from the scientific literature and are not medical or dosing guidance.

The favorable tolerability record applies to low-concentration topical products, where copper stays largely in the skin and total exposure is small. It does not transfer to injected or systemic use, for which controlled human safety data do not exist and where copper delivery raises unresolved questions about accumulation.

At a glance

Dosing

GHK-Cu (copper tripeptide-1) has no approved injectable or systemic human dose. The documented figures come from two places: topical cosmetic use on skin and in-vitro cell work, where concentrations are given as percentages or in the nanomolar to micromolar range. GHK also occurs naturally in human plasma, where its level declines with age. The numbers below are study and formulation concentrations reported in the literature, not injection instructions.

There is no established injectable or systemic human dose for GHK-Cu, and the primary reviews do not publish a single agreed topical percentage. These values describe concentrations used in cell experiments and cosmetic study creams, plus the naturally occurring plasma range, and are provided for laboratory research use only.

Preparing it

The vial ships as a lyophilized powder and is reconstituted with bacteriostatic water (or sterile water for single-session work) before use. Copper peptides are typically a deep blue in solution, and the vial should be swirled gently, never shaken, and drawn down the side of the glass until fully dissolved. Choose a diluent volume that gives a concentration convenient to read on a U-100 syringe. See reconstitution for the method and the concentration formula for working out the diluent. Store reconstituted material cold at 2-8 C and protected from light.

Where to go next

Last updated on July 3, 2026