GHK-Cu
Copper-binding tripeptide
A copper-binding tripeptide studied in dermal-research and tissue-remodeling contexts.
Overview
GHK is a naturally occurring tripeptide (glycyl-L-histidyl-L-lysine) found in human plasma, with levels reported to decline with age. GHK-Cu is its complex with copper(II) ions and is widely used as a cosmetic ingredient.
At a glance
What GHK-Cu does
GHK-Cu is a naturally occurring copper-binding tripeptide (glycyl-L-histidyl-L-lysine complexed with copper II) that acts primarily as a signaling molecule for skin repair and extracellular-matrix remodeling. Its defining action is that it behaves as a broad transcriptional modulator: gene-expression profiling work has reported that GHK-Cu up- or down-regulates on the order of thousands of human genes, and in cultured aged fibroblasts it has been shown to shift the expression pattern back toward that of younger cells. In practical terms, this translates into stimulation of fibroblast proliferation and coordinated upregulation of the genes that build the dermal matrix.
Mechanistically, GHK's high affinity for copper(II) lets it shuttle copper to enzymes and signaling pathways that depend on it. It increases synthesis of type I collagen, elastin, and the proteoglycans decorin, dermatan sulfate and chondroitin sulfate, while simultaneously rebalancing the matrix-metalloproteinase (MMP) system — tempering the collagen-degrading enzymes and their inhibitors (TIMPs) so that remodeling favors rebuilding over breakdown. It also has documented antioxidant and anti-inflammatory signaling effects and promotes angiogenesis (new blood-vessel formation) in healing tissue.
The evidence base is unusually deep for a cosmetic peptide but mixed in quality: much of the mechanistic and remodeling data comes from in-vitro fibroblast cultures and animal wound-healing models (rats, mice, rabbits, pigs). Human data exist — small topical trials have reported improved skin firmness, reduced fine lines and increased collagen versus controls — but they are limited in size. GHK-Cu is used both topically (cosmetic) and, in the research-peptide market, injectably; the strongest controlled data are for topical skin application.
Effects reported in research
- Stimulates fibroblast proliferation and upregulates type I collagen and elastin synthesis in cultured human skin cells (in-vitro).
- Increases production of dermal proteoglycans — decorin, dermatan sulfate and chondroitin sulfate — that give skin its structural matrix (in-vitro).
- Rebalances the MMP/TIMP system, reducing excess collagen-degrading metalloproteinase activity so remodeling favors rebuilding (in-vitro).
- Accelerated wound closure and increased new blood-vessel formation (angiogenesis) in rat, mouse, rabbit and pig wound-healing models.
- Reported in gene-profiling studies to modulate thousands of human genes and shift aged-fibroblast expression toward a younger pattern (in-vitro).
- Raised tissue antioxidant enzyme levels and dampened inflammatory signaling in animal healing models.
- In small topical human trials, improved skin firmness and reduced visible fine lines/wrinkles, with reported collagen increases versus vitamin C and retinoic acid comparators.
- Supports hair-follicle environment via improved perfusion and matrix signaling (preclinical; overlaps with copper-peptide hair research).
Effects listed reflect findings reported in the research literature — many in animal or in-vitro models. Listing an effect is not a claim of efficacy or a therapeutic indication in humans.
Mechanism of action
GHK has a high affinity for copper(II) and is understood to act partly as a copper-delivery molecule, facilitating copper transport relevant to enzymatic and remodeling processes. In cell and skin research it has been associated with signaling that influences extracellular-matrix remodeling, collagen and glycosaminoglycan synthesis, and antioxidant and gene-expression effects. Much of this work is from in-vitro and skin studies.
Mechanistic description reflects published research-literature understanding. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
What it's studied for
Research contexts in which GHK-Cu appears in the literature. Listing a research area is not a claim of efficacy or a therapeutic indication.
Key characteristics
- A naturally occurring human tripeptide that binds copper(II) with high affinity
- Plasma levels are reported to decrease with age
- Widely incorporated into cosmetic skincare formulations
- Studied for extracellular-matrix and skin-remodeling signaling
- Acts in part as a copper-delivery peptide
Reported research dosing reference only
Educational reference, not dosing guidance. The figures below summarize amounts reported in published research and research-community protocols, provided for educational and research context only. They are not medical advice, not a recommendation, and not instructions for human use. GHK-Cu is a research compound.
GHK-Cu is documented both as a topical cosmetic active (expressed as a formulation percentage) and as a reconstituted research peptide. These are reference figures for research context only, not human dosing guidance.
- Topical cosmetic formulation: ~0.05%-2% GHK-Cu, most commonly 0.1%-1%
- Higher-tier cosmetic references: ~1%-3%
- Reconstituted research reference: ~1-2 mg cited in blend/stack protocol summaries
Research summaries describe a biphasic dose response, with matrix synthesis favored at low concentrations; short circulating half-life supports split dosing in blend protocols.
How it compares
GHK-Cu is the most established copper tripeptide in cosmetic use, distinguished from AHK-Cu by its sequence and from repair peptides like BPC-157 by its remodeling and copper-delivery focus.
Commonly studied alongside
Compounds frequently researched together with GHK-Cu in the literature. Cross-referenced for research context — not a usage or combination recommendation.
Handling & Stability
Lyophilized peptides are stored cold, protected from light, and reconstituted only at the time of intended in-vitro work.
- Avoid repeated freeze-thaw cycles
- Verify supplier lot and Certificate of Analysis
- Follow institutional lab-safety protocols
Analytical & COA Concepts
Reputable research suppliers publish a third-party Certificate of Analysis per batch. Key analytical concepts referenced in COAs include:
Category Context
GHK-Cu sits in the Cosmetic & Dermal area of the PeptiDex library.
- Entry type: Research compound reference
- Browse the full library →
- Glossary of terms →
Where researchers source GHK-Cu
For researchers studying GHK-Cu, third-party suppliers such as Practically Natty Peptides offer research-grade material with third-party Certificates of Analysis and US-based shipping.
View research-supplier listing →
Outbound link to a third-party research supplier. Inclusion does not constitute endorsement; all editorial content is developed independently.
Frequently asked questions
What is GHK-Cu?
GHK-Cu is a complex of the naturally occurring tripeptide GHK (glycyl-L-histidyl-L-lysine) with a copper(II) ion. The GHK sequence is a subfragment of the alpha-2 chain of type I collagen and is present in human plasma, where its level declines with age. It is studied primarily as a copper-delivery and skin-remodeling signal peptide.
What is GHK-Cu studied for?
In research and cosmetic-formulation literature it is studied for collagen and glycosaminoglycan synthesis in dermal fibroblasts, wound-model remodeling, and antioxidant/gene-modulating activity. It is characterized as a signaling peptide rather than a therapeutic drug, and is not FDA-approved for treating any condition.
Why is a higher GHK-Cu concentration not necessarily better?
Research summaries note a biphasic dose response: GHK-Cu stimulates matrix synthesis at low (picomolar to nanomolar) concentrations, but at higher concentrations it can also upregulate matrix-degrading enzymes. This is why most cosmetic formulation guidance centers on the low end of the topical range rather than maximizing concentration.
What topical concentration of GHK-Cu is typical?
Cosmetic formulation references cite roughly 0.05% to 2% GHK-Cu, with most serums in the 0.1-1% range and 1-3% sometimes described as a higher clinical-tier formulation. Its low molecular weight (~340 Da) is cited as favorable for penetrating the stratum corneum.
How does GHK-Cu differ from AHK-Cu?
Both are small copper-binding peptides used in skin and hair cosmetic research. GHK-Cu begins with glycine (Gly-His-Lys) and is the natural collagen-derived sequence, whereas AHK-Cu is a synthetic analog beginning with alanine (Ala-His-Lys) that was designed with a focus on hair-follicle applications.
Is GHK-Cu topical or injectable in research?
GHK-Cu appears in both contexts. In cosmetics it is used topically as a formulation percentage; in research-peptide settings it is also sold lyophilized for reconstitution. Framing depends entirely on the study design, and neither use is a form of medical treatment.
Answers are educational summaries of research-literature context and do not constitute medical advice. See the Research Library, COA guide, and Storage & Handling guide for more.