GHK-Cu: a three-amino-acid copper-chelating peptide that modulates approximately 31% of human genes at nanomolar concentrations.

What Is GHK-Cu?

GHK-Cu is the tripeptide glycyl-L-histidyl-L-lysine chelated to a copper(II) ion in a 1:1 molar ratio. Molecular weight of the peptide moiety: 340.4 Da. INCI designation: Copper Tripeptide-1. It occurs naturally in human plasma, saliva, and urine — not a synthetic invention, but a signaling molecule the body produces endogenously.

Plasma GHK levels measure approximately 200 ng/mL (10⁻⁷ M) at age 20 and decline to roughly 80 ng/mL by age 60 — a ~60% reduction over four decades ^[18]. That decline coincides with the well-characterized decrease in tissue regenerative capacity associated with aging. The peptide is also released from the extracellular matrix during tissue remodeling, acting as a local repair signal.

The GHK-Cu literature spans more than 50 years of peer-reviewed research. The compound has been studied in human fibroblast cultures, rodent wound and inflammation models, mouse burn models, human skin trials, lung injury studies, and gene-array analyses. Read the GHK-Cu copper peptide research overview for the full chemical and historical context.

What Is a Copper Peptide?

A copper peptide is a small peptide molecule chelated to copper(II) ions. GHK-Cu is the most studied, with a published literature dating to Pickart's 1973 isolation of the compound from human plasma albumin ^[18]. The copper(II) ion is essential — copper complexation increases the peptide's partition coefficient, enhances membrane permeability, and is required for most of the downstream biological effects documented in cell culture and animal studies ^[1][4].

What Does GHK-Cu Do?

GHK-Cu modulates approximately 31.2% of human genes with expression changes of 50% or greater — upregulating 59% and suppressing 41% of the affected set ^[2]. The pathways covered span tissue regeneration, inflammation suppression, antioxidant activation, DNA repair, and anti-cancer signaling. At 1–10 nanomolar concentrations in human fibroblast cultures, the peptide stimulates collagen synthesis independently of cell proliferation, with maximal stimulation at 10⁻⁹ M and measurable activity beginning as low as 10⁻¹² M ^[1].

The breadth of effect is the literature's defining characteristic. Most peptides act on one pathway. GHK-Cu acts like a master regulator — a control script, not a single-target agonist. That framing shapes how this site presents the evidence: finding by finding, model by model, mechanism by mechanism. See GHK-Cu mechanism of action for the pathway detail.

What Does GHK-Cu Do in the Body Endogenously?

In endogenous context, GHK is released from extracellular matrix albumin during tissue injury and remodeling, recruiting repair signaling at wound sites ^[18]. The copper ion it carries activates antioxidant enzymes including superoxide dismutase, reduces oxidative damage at the injury site, and triggers VEGF-mediated angiogenesis and FGF-2-mediated cell proliferation. The GHK triplet sequence itself is present in the alpha2(I) chain of type I collagen, suggesting in situ liberation by tissue proteases provides a locally-timed collagen-synthesis signal ^[1].

GHK-Cu in Skin Care Research

The largest human study in the GHK-Cu literature enrolled 71 women with mild-to-advanced photoaged skin. Daily application of GHK-Cu facial cream (0.1–1% concentration) for 12 weeks improved skin laxity, clarity, and appearance; reduced fine lines and wrinkle depth; and increased skin density and thickness as measured by ultrasound and profilometry ^[13]. No head-to-head randomized controlled trial has compared these effects against retinol or other active ingredients.

A second human study — a 13-patient RCT evaluating topical GHK-Cu after CO₂ laser resurfacing — found significantly higher patient satisfaction (P=0.04) in the treatment group, though objective erythema and wrinkle parameters did not reach statistical significance, likely due to the small sample size ^[15].

In vitro mechanistic data is more robust. At nanomolar concentrations, GHK-Cu upregulates collagen I and III gene expression, increases TIMP-1 levels (protective against matrix breakdown), and stimulates elastin and glycosaminoglycan synthesis in human fibroblast cultures ^[4]. The cellular evidence is consistently directional; the controlled human trial data is limited to topical formulations and short durations. See the full collagen synthesis research summary for the fibroblast findings.

Endogenous GHK-Cu: Natural Occurrence

GHK-Cu occurs naturally in human plasma (approximately 200 ng/mL at age 20, declining to ~80 ng/mL by age 60), as well as in saliva and urine ^[18]. It is also released from the extracellular matrix during tissue remodeling. The age-related plasma decline is documented in measurement studies and has informed hypotheses about GHK's role as a tissue-repair signal.

Where This Site Fits in the Literature

GHK-Cu Script is an instrument-grade reading of the published research. The study ledger on /research presents 20 primary findings indexed by model type — in vitro, rodent, human topical — with species, dose, route, and outcome recorded for each. The dosage page organizes research-context concentration data by route and study type, without extrapolating to human administration protocols. The GHK-Cu benefits page maps documented effects to the specific studies that measured them.

GHK-Cu is not FDA-approved for any therapeutic indication. It is recognized as a cosmetic ingredient (INCI: Copper Tripeptide-1) in topical formulations. No Phase 2 or Phase 3 clinical trials for systemic administration in humans are registered or completed. This site documents what has been studied; it does not advise on use.