GHK-Cu: uses, evidence and status | Inside Your Peptides

compound file

The answer, first. A copper-binding tripeptide found in human plasma, structurally identified in 1977, sold as a cosmetic ingredient and as a research chemical. The strongest evidence is for diabetic foot ulcer, graded C — small or open-label human only.

Multicentre randomised evaluator-blinded placebo-controlled trial: 98.5% versus 60.8% median area closure, infection in 7% versus 34%, both P<0.05 ³.

Manufacturer-authored, never approved, unreplicated in 32 years. Every other use — facial wrinkles, collagen in skin, injected for skin, post-laser erythema, and 1 more — grade D or E: animal or mechanism data only, or a claim the human trials have already tested and not supported.

What it is used for

Every use graded on its own evidence, not the compound as a whole. 6 outcomes, ranked by what the human record supports.

#outcome · human · animal · gradewhat the best evidence actually shows

01Diabetic foot ulcer1 RCT, positive · rat wound chambersgrade CMulticentre randomised evaluator-blinded placebo-controlled trial: 98.5% versus 60.8% median area closure, infection in 7% versus 34%, both P<0.05 ³. Manufacturer-authored, never approved, unreplicated in 32 years.

02Facial wrinkles1 RCT, null on objective endpoints · fibroblast and rat collagen datagrade DThe only randomised facial trial with blinded objective endpoints found no difference in wrinkles or skin quality. The single positive was a patient questionnaire, P=.04, in thirteen people ¹.

03Collagen in skinno biopsy endpoint · rats and cultured fibroblastsgrade DRat subcutaneous wound chambers: collagen at 344% of control against total protein at 230%, with type I and III mRNA up ⁴. No human biopsy or hydroxyproline endpoint exists ¹².

04Injected for skinzero trials of any design · rat granulation tissue, 1993grade DNo human has been randomised to injected GHK-Cu for a skin endpoint. The claim rests on rat wire-mesh wound chambers from 1993 ⁴. FDA excluded the injectable route by name ¹¹.

05Post-laser erythema1 RCT, negative · none for this endpointgrade EComputer image analysis and blinded evaluators found no earlier resolution of erythema after CO2 resurfacing ¹. This is a tested and failed indication, not an untested one.

06Venous stasis ulcer1 RCT, negative, n=86 · rat wound chambersgrade ERandomised, evaluator-blinded, 86 evaluable patients: 0.4% cream was statistically indistinguishable from inert vehicle and was beaten by silver sulfadiazine ². The largest controlled dataset, and negative.

gradewhat it means

ARegulatory approval, or multiple adequately-powered trials agreeing with each other

BAt least one well-powered human randomised trial, with the direction replicated

CSmall or open-label human trials only

DAnimal or mechanism data only, with no controlled human outcome

EA claim the human trials have already killed

How it works

The proposed mechanism, in three steps. A mechanism is a reason to run a trial, never a substitute for one.

1targetGHK holds one copper ion in a three-nitrogen cage: the N-terminal amine, a deprotonated amide nitrogen and the imidazole nitrogen ⁸.

2signalIn cultured fibroblasts collagen synthesis begins near one picomolar and peaks near one nanomolar. Decorin mRNA rises, biglycan falls ⁵.

3effectRat wound chambers accumulate connective tissue preferentially as collagen. Glutathione reduces the complex and releases the copper ion ⁴⁹.

What it does not do

Claims the current record does not support. Worth knowing before you set expectations.

not supported by the evidence

GHK-Cu rebuilds elastin. Never measured in a human. Measured once ever, in rats, where elastin rose nearly parallel to total tissue protein ⁴.
GHK-Cu raises lysyl oxidase. Zero studies in any tissue in any species. The cross-linking story is inference from copper being a cofactor, and nothing more.
GHK resets 4,000 genes. The source is a Connectivity Map analysis of COPD lung tissue, validated in lung fibroblasts using GHK without copper ⁷.
Plasma GHK falls with age. The 200 to 80 nanogram figure traces to a 1973 doctoral thesis, four years before the molecule was sequenced ⁶.

How it is used

What published protocols administered, and what the community reports doing. Descriptive on both counts, and never a recommendation.

routeTopical serum or cream is the studied route. Injection and microneedling are sold. FDA excludes injectable GHK-Cu by name ¹¹.

formatCosmetic serum or cream, or a blue lyophilised powder in a vial.

published dosesThe randomised facial trial stated no concentration at all ¹. The venous ulcer trial used 0.4% cream ². A permeation study used 0.68% aqueous ¹⁰. A registered 2026 split-wound trial uses 0.1% w/w gel once daily for 14 days ¹³. Supplier sheets for the raw material disagree by two orders of magnitude on use level.

human pharmacokineticsNo human pharmacokinetic data published.

reported conventionsAs reported on skincare and peptide forums, 2010 to 2026: topical serums somewhere between 0.1% and 2%, applied at night. Users keep them apart from low-pH vitamin C and from thiols. A minority report microneedling or subcutaneous use. Convention, not guidance.

commonly paired withAHK-Cu

This site does not publish protocols to follow. The doses above are what studies administered or what users report, stated as facts about the literature and the market. How protocols are structured, mixing and storage and the reconstitution calculator cover the arithmetic.

What to expect

Where a trial measured it, the trial. Where only the community reports it, that is said out loud.

onsetNo trial has measured onset for a cosmetic endpoint, because the one randomised facial trial found no objective difference at any timepoint ¹. As reported: eight to twelve weeks before anything is claimed. No trial measured that.

most common reportAs reported: smoother texture. The controlled trial that looked for exactly that with blinded evaluators found nothing ¹.

adverse effectsThe 86-patient venous ulcer trial reported a safety profile that did not separate 0.4% cream from vehicle ². As reported topically: stinging and transient blue staining. FDA cites immunogenicity risk from aggregation and impurities for the injectable route ¹¹.

the stop signalAs reported: loss of the blue colour, which is real evidence the copper complex has gone ⁸⁹. No clinical stopping rule has been published.

Approval and status

What regulators and sport bodies have actually said, separately from what the evidence shows.

approvalNot an approved drug. Sold as a cosmetic ingredient and as a research chemical.

FDACategory 2 on FDA's compounding safety-risk list as GHK-Cu for injectable routes of administration, citing immunogenicity and limited human data ¹¹.

sport [WADA]Not named. S0 catches any non-approved substance ¹⁴.

sold asresearch chemical

Covered in depth

These reports grade GHK-Cu at length and carry their own verified reference lists.

The GHK-Cu Report: 30 Routes, Products and Rivals Ranked by Evidence

Three randomised trials in forty years, two of them negative, and not one measurement of elastin in a living human. Topical GHK-Cu grades D. Sunscreen grades A.

Check the vial

The grade above describes a molecule studied under controlled conditions. It says nothing about the powder in a particular vial.

That gap is the one part of this market a reader can actually close. How to read a certificate of analysis covers the five measures in five minutes, and the 2026 audit grades vendors on the documents they publish against a rubric printed in full.

Questions we get

What is GHK-Cu used for?

Wrinkles, skin firmness and wound healing. The evidence splits hard by use. A 1994 diabetic foot ulcer trial was positive and grades C, weakened by manufacturer authorship and 32 years without replication.

Facial photoaging grades D: the one randomised trial with blinded objective endpoints found nothing. Post-laser erythema and venous stasis ulcers grade E, because randomised trials tested both and both failed. Injected use has no human trial at all.

How is GHK-Cu used?

Descriptively. Published work used topical formulations: 0.4% cream in the venous ulcer trial and 0.68% aqueous in a permeation study. A Phase 2 split-wound trial that started in February 2026 uses 0.1% w/w gel.

The randomised facial trial named no concentration. As reported on skincare forums between 2010 and 2026, serums run roughly 0.1% to 2%, applied at night and kept away from low-pH actives.

How long does GHK-Cu take to work?

For facial skin, no trial has established that it does. The only randomised trial with blinded objective endpoints measured erythema, wrinkles and skin quality across the study.

It found no difference at any timepoint, so there is no onset curve to report. The wound trials measured closure over weeks to three months. As reported, users describe eight to twelve weeks before claiming a change, which no trial has checked.

Is injectable GHK-Cu better than topical?

There is no human trial of injected GHK-Cu with a skin endpoint, of any design, so there is nothing to compare against. What is known is arithmetic: GHK-Cu is about 15.8% copper by mass, and an injection has no gut to regulate copper absorption.

FDA's compounding list now names GHK-Cu for injectable routes of administration as a category 2 substance, citing immunogenicity from aggregation and peptide-related impurities. The route the market sells is the excluded one.

Why is GHK-Cu graded D when the mechanism looks strong?

Because grades here track human outcomes, not mechanism. Forty years of fibroblast and rat data is a reason to run a trial, not a substitute for one. The single randomised facial trial found no difference in erythema, wrinkles or skin quality.

The sole positive was a patient questionnaire at P=.04, in thirteen people. The largest controlled dataset, an 86-patient ulcer trial, was negative and lost to a cheap generic antimicrobial.

References

Miller TR, Wagner JD, Baack BR, Eisbach KJ. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. 2006. PMID 16847171
Bishop JB, et al. A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers. J Vasc Surg. 1992. PMID 1495150
Mulder GD, et al. Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper. Wound Repair Regen. 1994. PMID 17147644
Maquart FX, et al. In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex in rat experimental wounds. J Clin Invest. 1993. PMID 8227353
Maquart FX, et al. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex. FEBS Lett. 1988. PMID 3169264
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. PMID 29986520
Campbell JD, et al. A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK. Genome Med. 2012. PMID 22937864
Bossak-Ahmad K, et al. Ternary Cu[II] complex with GHK peptide and cis-urocanic acid. Int J Mol Sci. 2020. PMID 32867146
Ufnalska I, et al. Intermediate Cu[II]-thiolate species in the reduction of Cu[II]GHK by glutathione. Inorg Chem. 2021. PMID 34781677
Li H, et al. Microneedle-mediated delivery of copper peptide through skin. Pharm Res. 2015. PMID 25690343
FDA. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks. Content current as of 22 April 2026. fda.gov
Mortazavi SM, et al. Topically applied GHK as an anti-wrinkle peptide: advantages, problems and prospective. BioImpacts. 2025. PMID 39963574
ClinicalTrials.gov NCT07437586. A Phase 2, randomized, double-blind, vehicle-controlled, split-wound study of topical GHK-Cu gel. Started 2 February 2026. clinicaltrials.gov
World Anti-Doping Agency. The Prohibited List, section S0 Non-Approved Substances. wada-ama.org

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