GHK-Cu (Copper Peptide) — Research Reference
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is a naturally occurring copper-binding tripeptide first identified in human plasma by biochemist Loren Pickart in the 1970s. It is one of the most thoroughly characterised copper peptides in the scientific literature, with research spanning wound healing, collagen synthesis, skin regeneration, antioxidant activity, and gene expression modulation.
Quick Reference
| Parameter | Reported Value |
|---|---|
| Full name | GHK-Cu (Glycyl-L-Histidyl-L-Lysine · Copper(II)) |
| Amino acids | 3 (Glycine, Histidine, Lysine) |
| Molecular weight | ~340 Da (peptide); ~403 Da (copper complex) |
| Half-life | Short in circulation (minutes); tissue-level effects reported to persist longer |
| Common reported doses | 1–2 mg per day (injectable) or topical application |
| Administration routes | Subcutaneous injection, topical |
| Storage (lyophilized) | Refrigerator preferred; protect from light |
| Storage (reconstituted) | Refrigerated; use within 4–6 weeks |
Overview
GHK-Cu is a naturally occurring tripeptide found in human plasma, saliva, and urine. Plasma concentrations decline significantly with age — approximately 200 ng/mL at age 20, declining to approximately 80 ng/mL by age 60 — a pattern consistent with age-related declines in skin healing, tissue repair, and collagen production.
Research has investigated GHK-Cu for its potential role in:
- Stimulating collagen and glycosaminoglycan synthesis in fibroblasts
- Promoting wound contraction and epithelial cell migration
- Modulating antioxidant enzyme expression (superoxide dismutase, catalase)
- Activating TGF-β signalling pathways involved in tissue remodelling
- Regulating gene expression: published research has reported that GHK-Cu appears to reset a range of genes associated with ageing toward a younger expression profile
- Hair follicle enlargement and hair growth promotion (via interaction with follicular keratinocytes and angiogenic factors)
The copper ion is integral to GHK-Cu’s activity — the copper-peptide chelate is the biologically active form. Copper plays a direct role in the activity of collagen-crosslinking enzymes (lysyl oxidase) and copper-zinc superoxide dismutase.
Reported Protocols
The following information represents commonly reported research approaches drawn from anecdotal accounts and published research. These are not medical recommendations.
Subcutaneous Protocol
Subcutaneous injection is the most commonly reported parenteral route in research contexts. Commonly reported doses range from 1 mg to 2 mg per day.
- Frequency: Daily or every other day subcutaneous injection is the most commonly described approach in anecdotal research accounts
- Duration: Commonly reported research periods of 4 to 12 weeks
- Localised vs systemic: Some researchers report injecting near the target area (e.g., scalp subcutaneous injection for hair-related research), though systemic distribution from any subcutaneous site is also reported
Topical Application
Topical GHK-Cu is widely used in cosmetic skincare formulations and is the most common consumer application. Topical research contexts involve application of solutions or serums containing GHK-Cu to the skin surface:
- Concentrations commonly studied range from 0.1% to 1% in topical formulations
- Penetration into deeper dermal layers is considered limited compared to injectable routes, though research supports efficacy for surface-level skin outcomes (texture, elasticity, wound healing)
- Topical application to the scalp is commonly described in hair-related research contexts
Combination Use
GHK-Cu is frequently described in combination with other peptides in research protocols focused on skin, wound healing, or anti-ageing outcomes. It is sometimes described alongside BPC-157 in healing-focused protocols, and alongside retinoids or growth factors in skin-focused research.
Reported Effects
The following effects have been reported in published research and anecdotal accounts. This list reflects the research landscape, not confirmed clinical outcomes.
Collagen Synthesis & Skin Regeneration
Research has investigated GHK-Cu for its potential role in stimulating fibroblast activity and increasing collagen, elastin, and glycosaminoglycan production. Human fibroblast studies have reported increased collagen synthesis in response to GHK-Cu treatment. Anecdotal reports in skin research contexts describe improvements in skin texture, firmness, and the appearance of fine lines over 8–12 week protocols.
Wound Healing
Multiple animal and in vitro studies have investigated GHK-Cu for its potential role in accelerating wound closure, promoting epithelial cell migration, and stimulating the formation of granulation tissue. The compound has been investigated as a wound care adjunct in some clinical settings.
Hair Growth & Follicle Stimulation
Research has investigated GHK-Cu for its potential role in hair follicle enlargement and hair growth. Anecdotal reports describe improvements in hair density and thickness following topical and subcutaneous scalp application over 12–24 week periods.
Antioxidant Activity
Research has reported that GHK-Cu upregulates antioxidant enzyme expression, including superoxide dismutase and catalase, potentially reducing oxidative stress at the tissue level.
Gene Expression Modulation
Published genomic research (Pickart and Margolina, 2017) has proposed that GHK-Cu modulates the expression of hundreds of genes, including genes associated with inflammatory pathways, tissue remodelling, and cellular repair processes. This broad gene regulatory activity is an active area of research interest.
Reported Side Effects
Reported side effects in research and anecdotal accounts include the following. This list does not constitute a comprehensive safety profile and should not be interpreted as predictive of individual outcomes.
| Side Effect | Frequency Reported |
|---|---|
| Injection site redness or mild pain | Common (any SubQ injection) |
| Skin discolouration at injection site | Occasionally reported with subcutaneous use |
| Mild nausea | Rarely reported |
| Topical irritation or redness | Occasionally reported with topical use on sensitive skin |
Copper considerations: At very high doses or with prolonged use, theoretical concerns around copper accumulation exist. GHK-Cu at research doses is generally reported as well-tolerated in anecdotal accounts. The tripeptide form of copper is distinct from ionic copper and is reported to have a favourable safety profile at standard doses.
The compound has not undergone comprehensive human safety trials in injectable research compound contexts.
Storage & Handling
Lyophilized Powder (Unreconstituted)
- Room temperature: Reported stable for several months when kept away from light and moisture
- Refrigerator (2–8°C): Preferred for extended storage; protect from light
- Freezer: Acceptable for long-term storage; avoid repeated freeze-thaw cycles
- Light sensitivity: The copper complex is light-sensitive; store in an opaque or amber vial
Reconstituted Solution
- Refrigerator (2–8°C): Use within 4–6 weeks of reconstitution
- Do not freeze a reconstituted solution
- Sterile saline or bacteriostatic water are both used as diluents in research contexts
- Discard if the solution changes colour significantly or shows particulate matter
- Note: GHK-Cu solutions are typically a pale blue-green colour due to the copper complex; this is normal
Reconstitution
Add the chosen diluent slowly along the inside wall of the vial. Swirl gently — do not shake. See the Reconstitution Guide for step-by-step instructions.
Frequently Asked Questions
Why is the copper complex important — can GHK alone be used? The copper ion is integral to GHK-Cu’s biological activity. The tripeptide GHK has a very high affinity for copper (Ka ~10¹⁷) and is naturally found as the copper complex in plasma. Most of the research on collagen synthesis, wound healing, and gene expression has been conducted on the copper-bound form. Research on GHK alone is more limited.
Is GHK-Cu safe for topical use? GHK-Cu is widely used in cosmetic skincare formulations and is generally regarded as well tolerated topically at concentrations up to approximately 1%. It does not carry the irritation profile of retinoids and is frequently described as suitable for sensitive skin in cosmetic research contexts.
How does GHK-Cu relate to anti-aging research? The age-related decline in plasma GHK-Cu concentrations, combined with its reported role in collagen synthesis, antioxidant enzyme upregulation, and gene expression remodelling, has made it a compound of interest in longevity and anti-ageing research. Research has investigated whether restoring GHK-Cu levels may partially counteract age-related tissue decline.
Can GHK-Cu be used for hair loss? Research has investigated GHK-Cu for its potential role in hair follicle biology. Studies have reported follicle enlargement and hair shaft diameter increases in animal models. Anecdotal reports in hair research contexts describe topical and subcutaneous scalp application for hair density. Results in anecdotal accounts are variable.
Related Pages
Goals: Skin & Hair · Recovery & Healing · Longevity · Inflammation
Class: Copper Peptides
Comparisons: BPC-157 vs GHK-Cu
References & Further Reading
- Pickart L, Vasquez-Soltero JM, Margolina A. (2015). GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International, 2015, 648108. PubMed →
- Pickart L, Margolina A. (2018). Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences, 19(7), 1987. PubMed →
- Gorouhi F, Maibach HI. (2009). Role of topical peptides in preventing or treating aged skin. International Journal of Cosmetic Science, 31(5), 327–345. PubMed →