Peptide Graded

All peptides / Skin

GHK-Cu

Copper-binding tripeptide

Also GHK Cu, GHKCu, GHK-Cu peptide, Copper peptide, Copper peptides, Copper tripeptide-1

Evidence
CAnimal and cell studies
FDA status
Not approvedas of 2026-10-27
Route
Several routes
Studies cited
0 human8 animal or cell

A copper-based ingredient sold in skin creams and injections for wrinkles, hair loss and healing. It speeds wound healing in rats, but no proper human trial exists.

Sold for

GHK-Cu is sold as an anti-aging and wound-healing peptide, in serums for wrinkles and hair thinning and as an injectable for recovery.

Studies say

Cell and animal work shows that GHK-Cu raises collagen production and speeds wound closure in rats, but the human evidence is limited to cosmetic tests reported inside reviews, which is why the grade is C.

Why grade C. For skin repair and wound healing, the use GHK-Cu is best known for, the primary studies in hand are cell cultures, rat and mouse experiments and one macaque hair model. The human cosmetic results that reviews describe come from manufacturer-run tests that are summarised and not published in full, so no controlled human trial with a known sample size can be named. 5678

FDA. GHK-Cu is not approved by the FDA for any use. As copper tripeptide-1 it is sold in cosmetics, which sit outside FDA drug approval. The FDA placed the injectable form in Category 2 of its compounding list in 2023 over safety risks, and the agency now lists that nomination as withdrawn; it plans to bring GHK-Cu before its Pharmacy Compounding Advisory Committee by the end of February 2027.

Written from 17 cited sources. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for
Smoother skin, thicker hair, and faster healing.
Can a US doctor prescribe it?
No prescription; it is a cosmetic ingredient.
Properly tested in people?
Not properly: animal or lab studies, or small uncontrolled human reports. No controlled human trial is cited.

Evidence checklist

  • Randomised controlled trial No randomized human trial citedno
  • Human study over 100 people No human trial with known sample sizeno
  • More than one research group Cell, rodent and macaque work; company testsno
  • Clinical outcomes, not surrogate markers Cosmetic results from unpublished product testsno
  • Human safety data beyond case reports No injection safety data in peopleno

Drawn from the cited studies below. A dash means the sources give no information.

What it is

GHK-Cu is a three-amino-acid peptide (glycine, histidine, lysine) bound to a copper ion. It was isolated from human plasma, where its concentration falls with age, and the same sequence sits inside type I collagen, which led to the idea that it is released when collagen is broken down at a wound. 56

The copper matters. GHK binds copper tightly, and most of the biological work has been done with the copper complex, written GHK-Cu, so results for the two forms are not interchangeable. In skincare ingredient lists it appears as copper tripeptide-1. 54

How it works

In cultured fibroblasts, the cells that make the skin's structural proteins, GHK-Cu increased collagen synthesis at very low concentrations without changing the number of cells. The same group later showed in rats that it raised collagen, DNA, protein and glycosaminoglycan content in an implanted wound chamber in a concentration-dependent way, with type I and III collagen messenger RNA going up while TGF-beta did not. 67

Gene-expression work from Pickart's group, using the Broad Institute's Connectivity Map, reports that GHK shifts the activity of a large share of human genes, including those for antioxidant enzymes and DNA repair. These are computational predictions from cell-line data, which the authors present as hypotheses to test. 15161

What human research shows

No randomised human trial of GHK-Cu is in the citation set. The 2015 review lists cosmetic outcomes (firmer skin, fewer fine lines, less photodamage) drawn from product studies whose sample sizes and controls are not reported in a checkable way. 54

StudyModelFinding
Maquart 1988, fibroblast collagenHuman fibroblast culturesGHK-Cu stimulated collagen synthesis starting at picomolar concentrations, independent of cell number. 6
Maquart 1993, rat wound chamberRats, implanted wound chambers, saline controlInjected GHK-Cu raised collagen and glycosaminoglycan accumulation in the chamber in a concentration-dependent way; a control tripeptide had no effect. 7
Canapp 2003, ischemic wounds24 rats, topical gel versus vehicle and untreatedWound area fell 64.5% by day 13 in the treated group against 28.2% in untreated controls, with lower TNF-alpha and MMP levels in treated wounds. 8
Fu 2015, ACL reconstruction72 rats, intra-articular injection versus salineGraft laxity and stiffness were better at 6 weeks but the difference was gone by 12 weeks once treatment stopped. 2

Safety

In the animal and cell studies cited, no toxicity is described at the concentrations used, and the molecule is a natural plasma constituent. Nothing in these sources speaks to the safety of injecting GHK-Cu in people; the FDA's listing of the injectable form as a significant safety risk for compounding reflects that absence of data. 517

Questions for your clinician

  • Is there a controlled human trial for the use I have in mind?
  • Is a cosmetic cream or an injection what the evidence covers?
  • Why did the FDA flag the injectable form for compounding?

Questions people ask

What kind of molecule is GHK-Cu, and what does it do in the body?

GHK-Cu is a copper-binding tripeptide found in human plasma, with levels that decline from young adulthood onward. Its proposed role is as a signal released at injury sites: it draws immune and blood-vessel cells to a wound and tells fibroblasts to make more collagen and other matrix components. Most of that picture comes from cell cultures and rodent wound models. 567

Does GHK-Cu boost collagen, according to the studies?

In fibroblast cultures GHK-Cu raised collagen synthesis at concentrations far below those used in skincare, and in rats the injected complex increased collagen, elastin precursors and glycosaminoglycans in healing tissue. The increase in collagen was about twice the increase in other proteins. Whether topical creams reach the dermis at effective concentrations is not established by these studies. 67

What role might GHK-Cu play in healing wounds?

In a rat model of poorly perfused wounds, a 2% topical gel shrank wounds faster than vehicle or no treatment and lowered inflammatory markers in the wound bed. Pickart's review describes faster healing in dog paw pads and in rat, mouse and pig models. Human wound trials are not in the cited literature. 85

Is there any support for GHK-Cu as a treatment for thinning hair?

The hair evidence is thin. A copper-binding peptide enlarged hair follicles on the backs of rats in a 1993 macaque-model review, an effect the authors compared to topical minoxidil, and a 1991 mouse study reported follicle stimulation. The often-cited 2007 human follicle study used a different peptide, AHK-Cu, grown ex vivo, so it does not test GHK-Cu directly. 91110

Citations

  1. Pickart 2017, Brain Sciences: GHK and gene expression relevant to nervous system function doi.org
  2. Fu 2015, Journal of Orthopaedic Research: GHK-Cu in a rat ACL reconstruction model doi.org
  3. Park 2016, Oncotarget: GHK-Cu in LPS-induced acute lung injury in mice doi.org
  4. Pickart 2018, International Journal of Molecular Sciences: regenerative actions of GHK-Cu and gene data pmc.ncbi.nlm.nih.gov
  5. Pickart 2015, BioMed Research International: GHK as modulator of skin regeneration pathways pubmed.ncbi.nlm.nih.gov
  6. Maquart 1988, FEBS Letters: collagen synthesis in fibroblast cultures pubmed.ncbi.nlm.nih.gov
  7. Maquart 1993, Journal of Clinical Investigation: connective tissue accumulation in rat wounds pubmed.ncbi.nlm.nih.gov
  8. Canapp 2003, Veterinary Surgery: topical tripeptide-copper complex on ischemic open wounds pubmed.ncbi.nlm.nih.gov
  9. Uno 1993, Journal of Investigative Dermatology: chemical agents and peptides affect hair growth pubmed.ncbi.nlm.nih.gov
  10. Pyo 2007, Archives of Pharmacal Research: AHK-Cu on human hair growth in vitro pubmed.ncbi.nlm.nih.gov
  11. Trachy 1991, Annals of the NY Academy of Sciences: peptide copper complexes and hair follicles in C3H mice pubmed.ncbi.nlm.nih.gov
  12. Cutis 2005: mechanism of action of topical retinoids pubmed.ncbi.nlm.nih.gov
  13. Griffiths 1995, Archives of Dermatology: two concentrations of tretinoin for photoaging, RCT pubmed.ncbi.nlm.nih.gov
  14. FDA Drugs@FDA: tretinoin application 021108 accessdata.fda.gov
  15. Pickart 2012, Oxidative Medicine and Cellular Longevity: GHK-Cu, oxidative stress and aging pmc.ncbi.nlm.nih.gov
  16. Pickart 2014, BioMed Research International: GHK and DNA pmc.ncbi.nlm.nih.gov
  17. FDA: bulk drug substances nominated for use in compounding under section 503A, category list fda.gov

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