Pinc PeptideThe girly peptide research blog

GHK-Cu · Dose evidence · updated 8 October 2026

GHK-Cu dosage: what studies actually used

The short answer

Controlled trials in people have tested only creams, gels and serums of GHK-Cu: a 0.4% cream on leg ulcers, a gel once a day on diabetic foot ulcers, a serum twice a day for 8 weeks on facial wrinkles and a 2% serum twice a day for 12 weeks on eyebrows1234. We found no human study of GHK-Cu injected on its own, so no injectable dose is established56. Even the skin evidence is thin: a 2026 review of cosmetic uses included 20 studies, of which 18 were preclinical and only 2 were randomized trials7.

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

StudyWhoPeopleDose and routeWhat happened
Bishop 1992, randomized evaluator-blinded trial Adults with venous leg ulcers (86 who completed it; number randomized not given) 86 0.4% copper tripeptide cream, compared with placebo and with 1% silver sulfadiazine cream
On the ulcer · Not stated in the abstract		 The GHK-Cu cream did no better than placebo, and silver sulfadiazine, a standard antibacterial cream, shrank ulcers more than both2.
Badenhorst 2016, randomized double-blind split-face trial Women aged 40 to 65; 20 compared GHK-Cu with a plain serum on opposite sides of the face 40 GHK-Cu serum in nano-carriers, twice a day
On the face · 8 weeks		 Against the plain serum, wrinkle volume fell 24.1% vs 15.0% and wrinkle depth 20.3% vs 15.3%; the serum’s maker funded the trial, and in the other arm 1 woman stopped after minor reactions on both sides of the face, one side treated with a different product3.
Bo 2026, randomized double-blind placebo-controlled trial Adults with thin eyebrows; one eyebrow got GHK-Cu and the other placebo 18 2% serum, twice a day
On the eyebrows · 12 weeks		 Hair count rose from the starting count on the GHK-Cu side but not significantly on the placebo side; the authors report more and thicker hairs than on the placebo side, mainly by week 12, but give no statistic for that comparison. No serious side effects or allergic reactions were reported; the journal is not indexed in PubMed4.
Miller 2006, randomized trial with blinded evaluators Adults after CO2 laser resurfacing around the mouth (13 who completed it; number randomized not given) 13 Skin-care products with or without GHK-Cu
On the skin · Assessed at 12 weeks		 Evaluators found no difference in redness, wrinkles or skin quality, though patients rated their skin quality higher with GHK-Cu (P = .04)8.
Mulder 1994, randomized evaluator-blinded multicenter trial Adults with diabetic foot ulcers caused by nerve damage – A metered dose of GHK-Cu gel (Iamin) once a day, with standard ulcer care
On the ulcer · Not stated in the abstract		 Median closure of plantar ulcers was 98.5% with the gel vs 60.8% with the plain gel, and among plantar ulcers treated right after debridement, ulcer infections were 7% vs 34%1.

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Only topical use has been tested in controlled human trials. Trials used a daily metered dose of GHK-Cu gel on diabetic foot ulcers1, a 0.4% cream on venous ulcers2, a nano-carrier serum twice daily for 8 weeks on the face3, and a 2% serum twice daily for 12 weeks on the eyebrows4. We found no human study of an injected dose of GHK-Cu on its own6. The two published human reports of injected copper peptide we found used multi-ingredient scalp injections for hair loss, and neither the full text of one nor the abstract of the other gives the amount of copper peptide1011.

In animal studies

In mice with drug-induced lung fibrosis, GHK-Cu was injected into the abdomen (intraperitoneally) at 0.2, 2 or 20 µg/g on alternate days12. In a mouse model of Alzheimer’s disease, it was given into the nose at 15 mg/kg three times a week for 3 months13. In rats, it was injected at several concentrations into wound chambers implanted under the skin14.

What users report Anecdotal · not validated · not a recommendation

One dosing page aimed at injectors lists 1 to 2 mg injected under the skin once a day, 5 days a week, or 2 mg three times a week. The same page says the published human evidence is mostly topical or wound-focused and does not validate a universal injectable dose9.

Half-life and how it is taken

Half-life
No human value found15In rats given GHK intravenously, it was rapidly broken down to the dipeptide HK, which was also cleared rapidly; the abstract gives no numeric half-life. We found no human data for any route.
Routes
  • Topical creams, serums and gels (human trials)
  • Wound gels and dressings (human trials)
  • Subcutaneous injection (common in gray-market use; we found no human studies of GHK-Cu alone)
  • Scalp injection as one ingredient of hair-loss mixtures (two uncontrolled human studies)
  • Intraperitoneal injection and intranasal (animal studies only)

Skin products were tested; injecting it alone was not

Every controlled human trial of GHK-Cu we found applied it to the skin, a wound or the eyebrows12348, and we found no human study that injected it on its own6. The only published human reports of injected copper peptide we found are two uncontrolled hair-loss studies of multi-ingredient scalp injections1011. Results were mixed: a gel helped diabetic foot ulcers close, a cream did no better than placebo on leg ulcers, and a serum reduced wrinkles in a trial funded by its maker123.

Even the community dosing page that lists injection schedules says the published human evidence is mostly topical or wound-focused and does not validate a universal injectable dose9. A 2026 review adds that no validated human safety threshold exists for GHK-Cu or its free copper5.

What is known about injecting it

FDA says compounded GHK-Cu injections may cause immune reactions, because the peptide can clump (aggregate) and carry impurities16. A researcher who studies GHK-Cu names copper overload as a possible risk of injecting it, and copper is a known skin allergen for some people517.

A doctor of nursing practice who runs a clinic near Seattle told NPR that people who inject GHK-Cu have come in with injection-site irritation, infections and, in some cases, raised liver enzymes and copper levels; NPR noted it is unclear whether GHK-Cu, other undisclosed substances or impurities caused them17.

Under FDA’s interim policy, the agency does not intend to act against pharmacies that compound non-injectable GHK-Cu while it decides whether to add it to its list, but injectable GHK-Cu is outside that policy; FDA plans to consult its advisory committee before the end of February 2027161819. Vial quality varies: 43 of Finnrick’s latest 200 GHK-Cu tests, run from 23 June to 25 September 2026, failed its default standard of at least 99.5% purity and a dose within 35% of the label20.

Questions people ask

How much GHK-Cu should I use?

No dose of GHK-Cu is established for injection: we found no human study that injected it on its own56. Skin studies used a 0.4% cream, a daily gel on foot ulcers, a serum twice a day for 8 weeks and a 2% serum twice a day for 12 weeks1234. GHK-Cu is not an approved drug, and FDA’s interim policy for pharmacies does not cover injectable GHK-Cu181921.

Is it safe to inject GHK-Cu everyday?

We found no study of GHK-Cu injected on its own in people, daily or otherwise, so its safety by injection is unknown56. Two uncontrolled hair-loss studies injected it into the scalp as one ingredient of a mixture, every 3 weeks or once a month: one reported the treatment was well tolerated, and the other found slight pain from the injections in 3.4% of patients and slight bleeding in 0.3%, but neither can show what GHK-Cu itself does1011. FDA warns that compounded injections may cause immune reactions, and a GHK-Cu researcher names copper overload as a possible risk1617. A clinician near Seattle told NPR of injection-site irritation, infections and, in some cases, raised liver enzymes and copper levels in people who inject it, though the cause is unclear17.

Does GHK-Cu work better injected than on the skin?

We found no study comparing the two, and no human study that injected GHK-Cu on its own6. The skin evidence is itself limited: a 2026 review of cosmetic uses included only 2 randomized trials among its 20 studies, most of them preclinical, and results ranged from no benefit on leg ulcers to modest wrinkle reduction in a maker-funded trial237.

Go deeper

Sources

  1. 1Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper Wound Repair and Regeneration, Oct 1994. pubmed.ncbi.nlm.nih.gov
  2. 2A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers Journal of Vascular Surgery, Aug 1992. pubmed.ncbi.nlm.nih.gov
  3. 3Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters Journal of Aging Science, 22 Dec 2016. doi.org
  4. 4The efficacy of 2% copper peptide (GHK-Cu) serum for eyebrow hypotrichosis: a randomized, double-blind, vehicle-controlled, split-face comparative study Procedia of Multidisciplinary Research, 22 May 2026. so09.tci-thaijo.org
  5. 5GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo: Coordination Chemistry, Formulation Science, Therapeutic Evidence, and a Translational Roadmap Pharmaceutics, 27 Aug 2026. pmc.ncbi.nlm.nih.gov
  6. 6PubMed search: GHK-Cu or copper peptide names with injection terms (28 results; two injected people, each with a copper peptide as one ingredient of a hair-loss mixture) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  7. 7The Regenerative Potential of GHK-Cu in Aesthetic Medicine Aesthetic Surgery Journal, 20 Aug 2026. pubmed.ncbi.nlm.nih.gov
  8. 8Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin Archives of Facial Plastic Surgery, Jul 2006. pubmed.ncbi.nlm.nih.gov
  9. 9GHK-Cu (50 mg Vial) Dosage Protocol PeptideDosages.com, 26 Sep 2026. peptidedosages.com
  10. 10Intradermal injections of a hair growth factor formulation for enhancement of human hair regrowth - safety and efficacy evaluation in a first-in-man pilot clinical study Journal of Cosmetic and Laser Therapy, Oct 2018. pubmed.ncbi.nlm.nih.gov
  11. 11Androgenetic Alopecia Treatment in Asian Men The Journal of Clinical and Aesthetic Dermatology, Jul 2018. pubmed.ncbi.nlm.nih.gov
  12. 12Protective effects of GHK-Cu in bleomycin-induced pulmonary fibrosis via anti-oxidative stress and anti-inflammation pathways Life Sciences, 15 Jan 2020. pubmed.ncbi.nlm.nih.gov
  13. 13Behavioral and neuropathological features of Alzheimer’s disease are attenuated in 5xFAD mice treated with intranasal GHK peptide Aging Pathobiology and Therapeutics, 2024. pubmed.ncbi.nlm.nih.gov
  14. 14In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds The Journal of Clinical Investigation, Nov 1993. pubmed.ncbi.nlm.nih.gov
  15. 15Simultaneous determination of glycyl-L-histidyl-L-lysine and its metabolite, L-histidyl-L-lysine, in rat plasma by high-performance liquid chromatography with post-column derivatization Journal of Chromatography B, 25 Apr 1997. pubmed.ncbi.nlm.nih.gov
  16. 16Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  17. 17The copper peptide trend has gone from creams to injections — ahead of the science NPR, 7 Sep 2026. npr.org
  18. 18Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  19. 19Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act U.S. Food and Drug Administration, 14 May 2026. fda.gov
  20. 20GHK-Cu: vendor test results Finnrick, 25 Sep 2026. finnrick.com
  21. 21Drugs@FDA search for products containing prezatide (openFDA drugsfda endpoint; no matches) U.S. Food and Drug Administration (openFDA), accessed 1 Oct 2026. api.fda.gov · data query

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.