GHK-Cu
updated
What is GHK-Cu?
GHK-Cu is the tripeptide Gly-His-Lys coordinated to copper. Free GHK, copper-bound GHK, a chemically linked GHK conjugate, and a finished serum are related but not interchangeable interventions.
In a randomized 181-person diabetic-ulcer trial, the immediate-treatment plantar subgroup using topical Iamin 2% Gel had 98.5% median closure versus 60.8% with vehicle under standardized care. Delayed-treatment arms did not outperform vehicle. A separate venous-ulcer cream trial was null, and the hair trial tested a 5-ALA-GHK conjugate rather than GHK-Cu alone.
copper-bound tripeptide
- Gly-His-Lys bound to copper
- Topical delivery depends on formulation
- Human wound evidence is mixed and product-specific
- Injectable GHK-Cu has no established clinical benefit
What exactly is GHK-Cu?
GHK-Cu is the tripeptide Gly-His-Lys coordinated to copper. Free GHK, copper-bound GHK, a chemically linked GHK conjugate, and a finished serum are related but not interchangeable interventions.
The copper complex is hydrophilic, so the formulation and the condition of the skin barrier help determine whether a topical product reaches living tissue.
Delivery review · stratum-corneum limits
Formulation review
Ogórek R et al. Molecules, 2025.
The review describes GHK-Cu as hydrophilic and identifies the stratum corneum as a major delivery barrier. It says evidence for liposomal transport is still scarce, so ingredient presence does not prove delivery to a biological target.
- Study design
- Narrative review of topical delivery systems
Does topical GHK-Cu improve skin, wounds, or hair in people?
In a randomized 181-person diabetic-ulcer trial, the immediate-treatment plantar subgroup using topical Iamin 2% Gel had 98.5% median closure versus 60.8% with vehicle and a threefold faster closure rate under standardized care. Delayed-treatment arms did not outperform vehicle. A separate venous-ulcer cream trial was null. A small hair trial used a 5-ALA-GHK conjugate, so it did not isolate GHK-Cu.
| Study | Exact intervention | Result |
|---|---|---|
| Diabetic plantar ulcers · immediate treatment | Once-daily topical Iamin 2% Gel plus standardized wound care | 98.5% median closure vs 60.8% with vehicle; three times faster |
| Diabetic plantar ulcers · delayed treatment | Four weeks of vehicle, then Iamin 2% or 4% Gel | No significant improvement over vehicle |
| Venous ulcers | 0.4% copper tripeptide cream | No difference from vehicle |
| Male pattern hair loss | 5-ALA linked to GHK | Hair-count signal, but GHK-Cu was not isolated |
Among the immediate-treatment plantar groups, infection incidence was 7% with Iamin 2% Gel versus 34% with vehicle. The result applies to that wound-care protocol, not a cosmetic serum or injection.
Diabetic-ulcer RCT · 181 participants
Multicenter randomized evaluator-blinded placebo-controlled trial
Mulder GD et al. Wound Repair and Regeneration. 1994;2(4):259-269. doi:10.1046/j.1524-475X.1994.20406.x. PMID: 17147644.
In the immediate-treatment plantar subgroup, Iamin 2% Gel increased median closure to 98.5% versus 60.8% with vehicle, increased the proportion healing at least 98%, and produced a threefold faster closure rate. Infection incidence was 7% versus 34%. Delayed-treatment arms did not significantly outperform vehicle.
- Participants / model
- 181 people with diabetes and lower-extremity ulcers; the headline plantar comparison included 28 immediate Iamin 2% Gel participants and 32 immediate vehicle participants
- Treatment
- Once-daily topical Iamin 2% Gel or vehicle immediately after debridement, plus standardized pressure-relieving footwear and diabetes-care education; separate arms began Iamin 2% or 4% Gel after four weeks of vehicle
- Follow-up
- Up to 8 weeks of immediate treatment followed by 6 weeks of observation; delayed arms began active treatment after 4 weeks of vehicle
- Study design
- Multicenter randomized evaluator-blinded placebo-controlled trial
The positive closure and infection findings came from the immediate-treatment plantar subgroup. They do not establish benefit from a cosmetic serum or injection.
Read the original sourceVenous-ulcer RCT · no benefit over vehicle
Randomized evaluator-blinded trial
Bishop JB et al. Journal of Vascular Surgery, 1992.
Among 86 evaluable patients, silver sulfadiazine reduced ulcer size more than either 0.4% copper tripeptide cream or vehicle. Copper tripeptide and vehicle did not differ.
- Participants / model
- 86 evaluable adults with venous stasis ulcers
- Treatment
- 0.4% biologically active tripeptide copper cream, silver sulfadiazine cream, or vehicle
- Study design
- Prospective randomized evaluator-blinded comparative trial
This directly contradicts a broad claim that topical GHK-Cu reliably accelerates human wound healing.
Read the original sourceHair trial · 5-ALA-GHK conjugate
Randomized controlled trial
Lee WJ et al. Annals of Dermatology, 2016.
The 45-person study reported higher hair counts in active groups at six months, but the intervention was a chemical complex containing 5-aminolevulinic acid and GHK. It does not isolate GHK-Cu or an ordinary copper-peptide serum.
- Participants / model
- 45 men with androgenetic alopecia
- Treatment
- Topical 5-aminolevulinic acid and GHK complex at two concentrations or placebo
- Follow-up
- 6 months
- Study design
- Placebo-controlled human trial
Adjacent formulation evidence only; it is not a trial of GHK-Cu alone.
Read the original sourceWhy is GHK-Cu still biologically interesting?
Cell, tissue, and animal studies report effects on gene expression, extracellular-matrix remodeling, inflammation, and wound models. Those experiments support research interest, but they do not predict a clinical result from a serum or injection.
Did the COPD study treat people?
No. It used tissue from eight people to identify a disease-associated signature and then tested GHK in cultured fibroblasts. The clinical-sounding source is laboratory evidence.
COPD study · tissue and cultured cells
Human tissue and cell study
Campbell JD et al. Genome Medicine, 2012.
Investigators profiled 64 lung-tissue samples from eight people with severe COPD, then exposed cultured lung fibroblasts to GHK. The work identified a gene-expression signature and cell-remodeling effects; no participant received GHK.
- Participants / model
- 64 lung samples from 8 people plus cultured fibroblasts
- Treatment
- Laboratory GHK exposure to cultured cells
- Study design
- Expression analysis and in vitro experiment
Human-derived material is not an administered-human clinical trial.
Read the original sourceCOPD study · tissue and cultured cells
Human tissue and cell study
Campbell JD et al. Genome Medicine, 2012.
Investigators profiled 64 lung-tissue samples from eight people with severe COPD, then exposed cultured lung fibroblasts to GHK. The work identified a gene-expression signature and cell-remodeling effects; no participant received GHK.
- Participants / model
- 64 lung samples from 8 people plus cultured fibroblasts
- Treatment
- Laboratory GHK exposure to cultured cells
- Study design
- Expression analysis and in vitro experiment
Human-derived material is not an administered-human clinical trial.
Read the original sourceRat wound study · matrix delivery
Animal study
Arul V et al. Life Sciences, 2007.
A GHK-incorporated collagen matrix improved selected wound-healing measures in diabetic rats. The experiment tested an engineered matrix in an animal wound, not a cosmetic serum or injection in people.
- Participants / model
- Diabetic rats with experimental wounds
- Treatment
- GHK incorporated into a collagen matrix
- Study design
- Controlled animal study
What is known about safety?
Cosmetic exposure and injection should be kept separate. Human injection safety, immune reactions, chronic systemic exposure, pregnancy, interactions, and risks from sterility, endotoxin, potency, and degradation remain inadequately characterized.
A topical product can still irritate skin, and its other ingredients may drive the reaction. An injected product bypasses the skin barrier and adds formulation and manufacturing risks that topical use does not answer.
FDA safety page · injectable GHK-Cu
FDA safety communication
U.S. Food and Drug Administration.
FDA lists injectable GHK-Cu because peptide impurities and aggregation may create immunogenicity risk and because human safety information is limited.
- Study design
- Agency safety summary
Delivery review · stratum-corneum limits
Formulation review
Ogórek R et al. Molecules, 2025.
The review describes GHK-Cu as hydrophilic and identifies the stratum corneum as a major delivery barrier. It says evidence for liposomal transport is still scarce, so ingredient presence does not prove delivery to a biological target.
- Study design
- Narrative review of topical delivery systems
Is GHK-Cu FDA approved?
No FDA-approved GHK-Cu drug was identified. FDA’s 503A list treats non-injectable GHK-Cu as a nominated substance under evaluation, while the injectable nomination was withdrawn and injectable GHK-Cu remains on FDA’s safety-risk page.
FDA 503A · route-specific review status
FDA regulatory document
US Food and Drug Administration, updated 14 May 2026.
FDA’s current document places non-injectable GHK-Cu in Category 1 for substances under evaluation and says the injectable nomination was withdrawn. Category 1 does not mean an approved drug or a positive final clinical judgment.
- Study design
- Current compounding-nomination status document
FDA safety page · injectable GHK-Cu
FDA safety communication
U.S. Food and Drug Administration.
FDA lists injectable GHK-Cu because peptide impurities and aggregation may create immunogenicity risk and because human safety information is limited.
- Study design
- Agency safety summary
Studies and sources
Diabetic-ulcer RCT · 181 participants
Multicenter randomized evaluator-blinded placebo-controlled trial
Mulder GD et al. Wound Repair and Regeneration. 1994;2(4):259-269. doi:10.1046/j.1524-475X.1994.20406.x. PMID: 17147644.
In the immediate-treatment plantar subgroup, Iamin 2% Gel increased median closure to 98.5% versus 60.8% with vehicle, increased the proportion healing at least 98%, and produced a threefold faster closure rate. Infection incidence was 7% versus 34%. Delayed-treatment arms did not significantly outperform vehicle.
- Participants / model
- 181 people with diabetes and lower-extremity ulcers; the headline plantar comparison included 28 immediate Iamin 2% Gel participants and 32 immediate vehicle participants
- Treatment
- Once-daily topical Iamin 2% Gel or vehicle immediately after debridement, plus standardized pressure-relieving footwear and diabetes-care education; separate arms began Iamin 2% or 4% Gel after four weeks of vehicle
- Follow-up
- Up to 8 weeks of immediate treatment followed by 6 weeks of observation; delayed arms began active treatment after 4 weeks of vehicle
- Study design
- Multicenter randomized evaluator-blinded placebo-controlled trial
The positive closure and infection findings came from the immediate-treatment plantar subgroup. They do not establish benefit from a cosmetic serum or injection.
Read the original sourceVenous-ulcer RCT · no benefit over vehicle
Randomized evaluator-blinded trial
Bishop JB et al. Journal of Vascular Surgery, 1992.
Among 86 evaluable patients, silver sulfadiazine reduced ulcer size more than either 0.4% copper tripeptide cream or vehicle. Copper tripeptide and vehicle did not differ.
- Participants / model
- 86 evaluable adults with venous stasis ulcers
- Treatment
- 0.4% biologically active tripeptide copper cream, silver sulfadiazine cream, or vehicle
- Study design
- Prospective randomized evaluator-blinded comparative trial
This directly contradicts a broad claim that topical GHK-Cu reliably accelerates human wound healing.
Read the original sourceHair trial · 5-ALA-GHK conjugate
Randomized controlled trial
Lee WJ et al. Annals of Dermatology, 2016.
The 45-person study reported higher hair counts in active groups at six months, but the intervention was a chemical complex containing 5-aminolevulinic acid and GHK. It does not isolate GHK-Cu or an ordinary copper-peptide serum.
- Participants / model
- 45 men with androgenetic alopecia
- Treatment
- Topical 5-aminolevulinic acid and GHK complex at two concentrations or placebo
- Follow-up
- 6 months
- Study design
- Placebo-controlled human trial
Adjacent formulation evidence only; it is not a trial of GHK-Cu alone.
Read the original sourceCOPD study · tissue and cultured cells
Human tissue and cell study
Campbell JD et al. Genome Medicine, 2012.
Investigators profiled 64 lung-tissue samples from eight people with severe COPD, then exposed cultured lung fibroblasts to GHK. The work identified a gene-expression signature and cell-remodeling effects; no participant received GHK.
- Participants / model
- 64 lung samples from 8 people plus cultured fibroblasts
- Treatment
- Laboratory GHK exposure to cultured cells
- Study design
- Expression analysis and in vitro experiment
Human-derived material is not an administered-human clinical trial.
Read the original sourceDelivery review · stratum-corneum limits
Formulation review
Ogórek R et al. Molecules, 2025.
The review describes GHK-Cu as hydrophilic and identifies the stratum corneum as a major delivery barrier. It says evidence for liposomal transport is still scarce, so ingredient presence does not prove delivery to a biological target.
- Study design
- Narrative review of topical delivery systems
Rat wound study · matrix delivery
Animal study
Arul V et al. Life Sciences, 2007.
A GHK-incorporated collagen matrix improved selected wound-healing measures in diabetic rats. The experiment tested an engineered matrix in an animal wound, not a cosmetic serum or injection in people.
- Participants / model
- Diabetic rats with experimental wounds
- Treatment
- GHK incorporated into a collagen matrix
- Study design
- Controlled animal study
FDA safety page · injectable GHK-Cu
FDA safety communication
U.S. Food and Drug Administration.
FDA lists injectable GHK-Cu because peptide impurities and aggregation may create immunogenicity risk and because human safety information is limited.
- Study design
- Agency safety summary
FDA 503A · route-specific review status
FDA regulatory document
US Food and Drug Administration, updated 14 May 2026.
FDA’s current document places non-injectable GHK-Cu in Category 1 for substances under evaluation and says the injectable nomination was withdrawn. Category 1 does not mean an approved drug or a positive final clinical judgment.
- Study design
- Current compounding-nomination status document
Why is GHK-Cu in S tier?
S reflects a positive randomized diabetic-foot-ulcer result plus broad cell and animal research. Human findings remain product and wound specific: one diabetic plantar-ulcer gel trial was positive, one venous-ulcer cream trial was null, and the hair trial used a 5-ALA-GHK conjugate. Injectable clinical benefit remains unestablished.
read GHK-Cu in the reptides guide, chapter 05: 7 pages, free to read.