GHK-Cu
Copper-binding tripeptide with systemic anti-inflammatory effects and the flagship peptide for skin, collagen, and wound healing.
GHK-Cu (GHK-Cu (Copper Peptide)). Copper-binding tripeptide with systemic anti-inflammatory effects and the flagship peptide for skin, collagen, and wound healing. Typical community dosing: 1–2 mg SC 2–3× weekly (systemic) or 0.05–0.2% topical (skin). Regulatory status: Not FDA-approved systemically.
3 residues· First described 1973
Tripeptide complexed with copper (Cu2+)
Overview
GHK-Cu is a tripeptide that naturally binds one atom of copper. It's found endogenously in plasma at levels that decline sharply with age, and is probably the most research-validated peptide for skin rejuvenation, collagen synthesis, and wound healing. It's the flagship compound of the "Glow Stack" (GHK-Cu + BPC-157 + Epithalon).
Systemic GHK-Cu has meaningful anti-inflammatory effects and upregulates a huge swath of repair-related genes. Topical application concentrates the skin effects but doesn't deliver the same systemic anti-inflammatory benefit.
Because GHK-Cu is a copper carrier, anyone using systemic doses regularly should check serum copper and ceruloplasmin at baseline. Chronic high-dose copper loading can cause problems. Most protocols run short cycles (6–12 weeks) with breaks.
Mechanism of Action
GHK-Cu upregulates genes involved in collagen synthesis, decorin and glycosaminoglycan production, angiogenesis, and anti-inflammatory cytokine response. It modulates over 4000 genes in published microarray analyses. Copper is the functional cofactor - it's not just a "peptide" but a peptide-metal complex that ferries copper to enzymes that need it (like lysyl oxidase for collagen cross-linking).
Community Usage Patterns
Systemic: 1–2 mg SC 2–3× per week for 6–12 week cycles. Topical serums: 0.05–0.2% applied once or twice daily to skin. Cycle recommendation: 6–12 weeks on, 4–6 weeks off, to avoid copper loading. Often stacked with BPC-157 (local tissue repair) and Epithalon (pineal/longevity) in the Glow Stack.
Education only - not medical advice. Any protocol change should involve your licensed provider.
Deep Dive
From young plasma to a copper shuttle: how GHK-Cu actually works
The tripeptide glycyl-L-histidyl-L-lysine was first isolated in 1973 by Loren Pickart, who was investigating why a fraction of human plasma drawn from younger donors made aged liver tissue behave more like young tissue. The active molecule was GHK, and its defining property is chemistry rather than sequence: the histidine-lysine motif binds copper(II) with unusually high affinity, close to that of albumin, a major copper-binding protein in blood. That is why GHK rarely functions as a bare peptide in the body. It works as a copper-delivery vehicle.
The distinction matters mechanistically. Copper is a mandatory cofactor for several enzymes that build and maintain connective tissue, and the GHK-Cu complex appears to ferry copper toward exactly those enzymes:
- **lysyl oxidase**, which cross-links collagen and elastin into durable fiber structure - **Cu/Zn superoxide dismutase (SOD1)**, a front-line antioxidant enzyme - **cytochrome c oxidase**, the terminal step of mitochondrial energy production
Beyond loading enzymes, research reports a transcriptional role. In gene-expression work summarized by Pickart and Margolina, low-micromolar GHK shifted large blocks of genes toward a more youthful, repair-oriented pattern, raising antioxidant, DNA-repair, and tissue-remodeling programs while lowering inflammatory and fibrotic signaling. Plasma GHK is reported to fall from roughly 200 ng/mL near age 20 to about 80 ng/mL by age 60, though that figure rests on a small number of measurements rather than large longitudinal data. That decline is the biological rationale offered for supplementation, but a falling biomarker is not by itself proof that replacing it changes any outcome.
What the human evidence really shows, and where it stops
The single most important thing to understand about GHK-Cu is that the strength of the evidence depends heavily on the route of administration.
The strongest human data is **topical and cosmetic**. Small facial studies of copper-tripeptide creams have reported improvements in measured skin firmness, density, and the appearance of fine lines over roughly 12 weeks, and copper-peptide wound dressings were commercialized in the 1990s on the back of topical healing data. These trials are real but modest. Small sample sizes, short duration, and frequent industry involvement mean they support "improved measured skin parameters" far better than any deep systemic anti-aging claim.
The most cited mechanistic finding in human tissue is not a clinical trial at all. In a 2012 Genome Medicine paper, Campbell and colleagues used the Broad Institute Connectivity Map to search for compounds that could reverse the gene-expression signature of emphysema-damaged human lung, and GHK surfaced as a candidate hit. Follow-up in cultured human lung fibroblasts showed GHK restored collagen expression and cell contraction. This is genuinely interesting, but it is a gene-signature and cell-culture result, not evidence that injected GHK-Cu treats lung disease in people.
**Systemic, injected GHK-Cu in humans is where the honesty has to be blunt.** There are essentially no controlled human trials of subcutaneous GHK-Cu for the anti-inflammatory, longevity, or whole-body repair uses it is marketed for. The systemic gene-modulation story rests on in-vitro and animal work. Anyone presenting injectable GHK-Cu as clinically evidence-backed is extrapolating well beyond what has actually been tested in humans.
The biomarkers commonly tracked on a copper-peptide protocol
Because GHK-Cu is a copper carrier, the tracking rationale differs from most peptides. The purpose is less about confirming efficacy and more about watching for copper accumulation, since the body has no rapid route to shed a copper surplus.
- **Serum copper and ceruloplasmin** are read together. Ceruloplasmin carries the large majority of circulating copper, commonly cited around 90 percent, so a serum copper that rises while ceruloplasmin lags can point to loosely bound "free" copper, the fraction most associated with oxidative stress. - **hs-CRP** is a general inflammation marker sometimes followed over time to see whether the systemic anti-inflammatory claims correspond to any measured change across a cycle. - **Ferritin** is an iron-status and acute-phase marker. Copper and iron metabolism are linked, so it adds context to an inflammation panel. - **Zinc**, where available, is worth watching because copper and zinc compete for absorption, and chronic copper loading can quietly depress zinc.
These are values to review and interpret with a licensed clinician, not to self-interpret. The educational takeaway is simple: on this compound, copper is the variable to respect.
Topical versus systemic, compounding, and the 2026 landscape
The two delivery routes are almost different compounds from a regulatory and safety standpoint. **Topical copper tripeptide**, known by the cosmetic ingredient name Copper Tripeptide-1, is a long-established, widely sold cosmetic component. It concentrates the skin effects and carries minimal systemic copper risk. **Injectable GHK-Cu** is another matter entirely. It is not an FDA-approved drug, it is not a standardized product, and it sits inside the same unapproved research-peptide category that has drawn intensifying scrutiny through the 2026 FDA compounding-review wave, in which injectable GHK-Cu was among the peptides removed from the interim Category 2 list pending individual advisory-committee review.
That regulatory posture is the honest context behind the short-cycle convention discussed in optimization circles. Limited runs with breaks are framed there as a way to reduce cumulative copper exposure, not as a validated dosing schedule with human outcome data behind it. None of this is medical advice, and none of it should be read as encouragement to obtain or self-administer an injectable peptide. Whether any form of GHK-Cu is appropriate for a given person is a decision for that person and a licensed clinician.
The defensible summary is narrow and worth stating plainly. GHK-Cu has solid in-vitro and topical human evidence for skin and wound biology, a genuinely interesting gene-modulation profile, and almost no controlled human data for the systemic uses that dominate its online reputation.
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci. 2018;19(7):1987.
- Campbell JD, McDonough JE, Zeskind JE, et al. A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK. Genome Med. 2012;4(8):67.
- Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol. 1973;243(124):85-87.
Biomarkers to Track
When running GHK-Cu, these are the biomarkers most commonly tracked to assess response and safety:
Blood Work Checklist
Before starting GHK-Cu, baseline the right panel. The Peptide Blood Work Checklist covers the full baseline panel, what to add for GHK-Cu's class, and when to retest.
See the peptide blood work checklist →Reconstitution Calculator
Free calculator for GHK-Cu reconstitution math - vial size, BAC water volume, and exact syringe units.
Open GHK-Cu calculator →Side Effects & Monitoring
What GHK-Cu side effects are commonly reported, when they appear, the red flags worth a provider call, and the biomarkers that catch issues early.
GHK-Cu side effects & what to track →Results & What to Track
What GHK-Cu results actually look like in the data - the markers to measure, when they tend to move, and how to tell a real result from placebo.
GHK-Cu results & how to measure them →Related Peptides
Stacks That Include GHK-Cu
GHK-Cu Head-to-Head Comparisons
Frequently Asked Questions
What is GHK-Cu?
GHK-Cu is a tripeptide that naturally binds one atom of copper. It's found endogenously in plasma at levels that decline sharply with age, and is probably the most research-validated peptide for skin rejuvenation, collagen synthesis, and wound healing. It's the flagship compound of the "Glow Stack" (GHK-Cu + BPC-157 + Epithalon).
How does GHK-Cu work?
GHK-Cu upregulates genes involved in collagen synthesis, decorin and glycosaminoglycan production, angiogenesis, and anti-inflammatory cytokine response. It modulates over 4000 genes in published microarray analyses. Copper is the functional cofactor - it's not just a "peptide" but a peptide-metal complex that ferries copper to enzymes that need it (like lysyl oxidase for collagen cross-linking).
What is the typical dosing for GHK-Cu?
1–2 mg SC 2–3× weekly (systemic) or 0.05–0.2% topical (skin)
What biomarkers should I track on GHK-Cu?
Common biomarkers tracked on GHK-Cu protocols: Serum copper, Ceruloplasmin, hs-CRP, Ferritin.
Log doses, upload your lab PDFs, and let StackAI read your panel in context of what you're actually running. Free to start.
Start tracking →This page is informational and does not constitute medical advice. MyProtocolStack is a tracking and education platform. Work with a licensed provider before starting, changing, or stopping any protocol.