GHK-Cu / Guide

GHK-Cu injectable vs topical: what's actually been studied

Almost everything known about GHK-Cu in people comes from creams and serums on the skin. Injected GHK-Cu has been tested in rats, not in controlled human trials.

By PeptideTracker editorial team · Updated November 9, 2026 · 16 sources

[00] Short answer

  1. Human studies of GHK-Cu are few, small and almost all on the skin. A 2026 review counted 4, the largest with 18 people6.
  2. We found no controlled human trial of GHK-Cu injections. The injection studies are in rats6,10–11.
  3. In the US, GHK-Cu for non-injectable use is “under evaluation” for compounding. The nomination for injectable GHK-Cu was withdrawn, and FDA flagged a risk of immune reactions and impurities1–2.
  4. In the one randomized wound trial, a GHK-Cu cream healed leg ulcers no better than placebo in 86 people9.
  5. No FDA-approved drug contains GHK-Cu3.

What's the difference between injectable and topical GHK-Cu?

It's the same copper peptide, but the route changes the evidence, the rules and the risks. Topical GHK-Cu is put on the skin, usually in a cream or serum. Injectable GHK-Cu is sold as powder or liquid to inject under the skin.

In the US, a product rubbed on the body to improve appearance is a cosmetic. It becomes a drug if it's meant to treat disease or change how the body works, and FDA judges that from claims, marketing and why people buy it4. Anything injected carries extra quality demands. A 2026 review lists sterility, endotoxin, particles, clumping, immune reactions and the body's total copper load as things an injectable GHK-Cu product would need to be tested for6.

What have GHK-Cu studies tested, by route?

Most GHK-Cu research is lab and animal work. A 2026 systematic review of GHK-Cu in aesthetic medicine found 20 studies, 18 of them preclinical and 2 randomized trials in people7.

GHK-Cu evidence by route (checked November 8, 2026)
RouteStudiesWhat they found
Lab cells and tissueMany studiesGHK-Cu increased collagen and other skin-support proteins and affected inflammation markers7
On the skin (people)A few small studies6Mixed. No objective benefit after laser treatment in 13 people8; better eyebrow hair in 18 people6; no better than placebo for leg ulcers in 86 people9
Injected (animals)Rat studiesMore collagen in implanted wound chambers10; a tighter knee after ligament surgery at 6 weeks, gone by 12 weeks11
Injected (people)No controlled trial of GHK-Cu alone foundFDA describes human safety data as limited2. The 2026 review found no human exposure data for injected or other systemic use6

A separate 2026 review concluded that GHK-Cu “should be regarded as a promising but unproven therapeutic cargo rather than a clinically validated regenerative drug”6.

Does topical GHK-Cu work for skin?

The human results for topical GHK-Cu are small and mixed. A 2026 review of everything tested in people found four studies: a 1998 cream comparison, a 2002 conference report, a post-laser study and a 2026 eyebrow study6. A 2025 review of GHK as an anti-wrinkle ingredient said that, despite its wide use in cosmetics, there is “a surprising absence of clinical studies”5.

  • After laser resurfacing: 13 people completed a randomized study. GHK-Cu skin care made no measurable difference to redness, wrinkles or skin quality, though users rated their skin better8.
  • Eyebrow hair: a 2026 split-face study in 18 healthy people reported more and thicker eyebrow hairs over 12 weeks with a GHK-Cu serum6.
  • Leg ulcers: in 86 people with venous ulcers, a GHK-Cu cream did no better than placebo. A silver sulfadiazine cream beat both9.

A phase 2 trial of a topical GHK-Cu gel on standard skin wounds (NCT07437586) was still recruiting in August 2026, with no results6.

Has GHK-Cu been tested as an injection in people?

Not in a controlled trial of GHK-Cu on its own, as far as we could find. The 2026 evidence review lists no human study of injected GHK-Cu, and found no human exposure data for injected or other systemic use6. FDA describes human safety data for injectable GHK-Cu as limited2.

The injection evidence comes from animals:

  • Rat wounds: GHK-Cu injected into wire-mesh chambers implanted under rats' skin increased collagen, protein and other tissue, more so at higher concentrations10.
  • Rat knees: in 72 rats after ligament (ACL) surgery, weekly knee injections for 4 weeks gave a tighter knee at 6 weeks, but the difference was gone by 12 weeks11.
  • Breakdown: injected into rats' veins, GHK was rapidly broken down and its breakdown product cleared quickly14. No human half-life for injected GHK-Cu has been published that we could find.

The closest thing to human injection data is an open-label clinic study in India. 1,000 people had scalp injections of a hair formula mixing several growth factors, thymosin beta-4 and a copper peptide listed as copper tripeptide-1. There was no comparison group, and with so many ingredients the study can't show what any one of them did15.

Is injectable GHK-Cu FDA approved or legal?

No form of GHK-Cu is an FDA-approved drug3. For pharmacy compounding, FDA treats the two routes differently. Non-injectable GHK-Cu is back in Category 1, “under evaluation”, after a nominator clarified in May 2026 that it had withdrawn only the injectable route1. The injectable nomination stays withdrawn. FDA lists it among substances that may carry a risk of immune reactions and impurities2. FDA plans to ask its Pharmacy Compounding Advisory Committee about GHK-Cu before the end of February 20271.

GHK-Cu regulatory status by route
Topical and other non-injectableInjectable
FDA-approved drugNo3No3
US compounding (503A)Category 1, “under evaluation” (May 14, 2026)1Nomination withdrawn; FDA flagged immune reaction and impurity risks2
CanadaNo product with GHK as an ingredient in Health Canada's drug database16Listed among seized unauthorized injectable peptides12. GHK-Cu powder was recalled from pharmacies in May 202613

In Canada, Health Canada named GHK-Cu among unauthorized injectable peptides it had seized, and warned that injectable peptides are generally prescription drugs12. A supplier also recalled GHK-Cu powder sold to pharmacies as an unauthorized active ingredient13. For how other peptides stand, see BPC-157 legal status.

Questions

Is GHK-Cu injection better than topical?

Nobody knows, because no study has compared them in people. Topical GHK-Cu has a few small human studies with mixed results. Injected GHK-Cu has only been tested in rats.

Is injectable GHK-Cu FDA approved?

No. No GHK-Cu product is FDA-approved. The nomination to use injectable GHK-Cu in pharmacy compounding was withdrawn, and FDA noted a possible risk of immune reactions and impurities. Non-injectable GHK-Cu is still under FDA evaluation for compounding.

Can compounding pharmacies make GHK-Cu?

FDA lists non-injectable GHK-Cu in Category 1, under evaluation, as of May 14, 2026. Injectable GHK-Cu isn't included. FDA plans to ask its Pharmacy Compounding Advisory Committee about GHK-Cu before the end of February 2027. Ask your pharmacist what that means for a specific product.

Does GHK-Cu cream work?

The evidence is thin and mixed. In 13 people after laser treatment it made no objective difference, a 2026 study in 18 people found better eyebrow hair growth, and in 86 people with leg ulcers it did no better than placebo.

What is the half-life of injected GHK-Cu?

It hasn't been published for people. In rats given GHK into a vein, it was broken down rapidly. A 2026 review says free GHK is expected to have a short half-life in the body, but that hasn't been measured in humans.

Sources

Checked against FDA's 503A category list (May 14, 2026) and safety risks page, Health Canada notices (2026), a 2026 systematic evidence review and the original studies on PubMed. How we check

  1. 1FDA: Bulk drug substances nominated for use in compounding under section 503A (Categories 1, 2 and 3). updated May 14, 2026; GHK-Cu update note on page 1 and Category 1 list
  2. 2FDA: Certain bulk drug substances for use in compounding that may present significant safety risks. 'Bulk drug substances nominated but withdrawn': GHK-Cu (for injectable routes); content current as of April 22, 2026
  3. 3FDA: Drugs@FDA, searched through openFDA for the active ingredient GHK-Cu. no approved product found, searched November 8, 2026
  4. 4FDA: Is it a cosmetic, a drug, or both? (Or is it soap?)
  5. 5Mortazavi SM et al. Topically applied GHK as an anti-wrinkle peptide: advantages, problems and prospective. BioImpacts. 2025;15:30071
  6. 6Mateescu DM et al. GHK-Cu as a bioactive metallopeptide and drug-delivery cargo: a translational roadmap. Pharmaceutics. 2026;18(9):1077. systematic evidence-mapping review; sections 6 to 9, human evidence in section 7.1
  7. 7Mokhtar J et al. The regenerative potential of GHK-Cu in aesthetic medicine. Aesthet Surg J. 2026. systematic review, 20 studies
  8. 8Miller TR et al. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg. 2006;8(4):252-259
  9. 9Bishop 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;16(2):251-257
  10. 10Maquart FX et al. In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex GHK-Cu in rat experimental wounds. J Clin Invest. 1993;92(5):2368-2376
  11. 11Fu SC et al. Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction. J Orthop Res. 2015;33(7):1024-1033
  12. 12Health Canada: Think twice before injecting peptides bought online (public advisory RA-81874). published April 9, 2026
  13. 13Health Canada: GHK-Cu & BPC-157 powder, unauthorized active pharmaceutical ingredients (recall RA-82047). Type I recall, May 5, 2026
  14. 14Endo T et al. Simultaneous determination of glycyl-L-histidyl-L-lysine and its metabolite in rat plasma by HPLC. J Chromatogr B. 1997;692(1):37-42
  15. 15Kapoor R, Shome D. Intradermal injections of a hair growth factor formulation for enhancement of human hair regrowth: a first-in-man pilot clinical study. J Cosmet Laser Ther. 2018;20(6):369-379
  16. 16Health Canada Drug Product Database, active ingredient search for GHK. no products found, searched November 8, 2026

This guide explains what labels and published studies say. It isn't medical advice and doesn't replace your prescriber or pharmacist.

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