AHK-Cu
updated
AHK-Cu is a copper-bound tripeptide, alanine-histidine-lysine, one amino acid away from GHK-Cu, found in topical hair products and also sold for injection. It is marketed for hair growth and pattern hair loss, riding GHK-Cu's reputation. In the one laboratory study, isolated human hair follicles grew longer and cultured dermal papilla cells multiplied at very low concentrations, but no trial has given AHK-Cu alone to people, so visible hair growth and human safety are untested. Graded C on that single follicle study and its cell findings; GHK-Cu's evidence does not transfer to it.
copper-bound tripeptide
- Ala-His-Lys bound to copper
- Distinct from GHK-Cu
- Published AHK-Cu findings are ex vivo and in vitro
- No established injectable use
What exactly is AHK-Cu?
AHK-Cu is alanine-histidine-lysine bound to copper. It differs from GHK-Cu by one amino acid, so evidence for one does not establish the other.
source: Human follicle study · ex vivo, not a patient trial, Pyo HK et al. Archives of Pharmacal Research, 2007.
Has AHK-Cu grown hair in people?
PubMed and ClinicalTrials.gov listed no administered-human AHK-Cu monotherapy trial. A multi-ingredient product study does not isolate AHK-Cu’s contribution.
source: PubMed and ClinicalTrials.gov · no exact human trial, PubMed and ClinicalTrials.gov records.
source: Combination study · AHK-Cu not isolated, Kapoor R et al. Journal of Cosmetic Dermatology, 2020.
What did the exact follicle study show?
AHK-Cu increased elongation of isolated human follicles and proliferation of cultured dermal papilla cells at very low laboratory concentrations. The apoptosis result was not statistically significant, and the study did not test scalp delivery or visible hair growth in a person.
source: Human follicle study · ex vivo, not a patient trial
source: Adjacent copper peptide · delivery caveat, Ogórek R et al. Molecules, 2025.
How does AHK-Cu compare with GHK-Cu or minoxidil?
AHK-Cu has a narrower exact evidence base than GHK-Cu and far less administered-human evidence than topical minoxidil. Structural similarity and shared marketing do not establish equal effect.
source: Human follicle study · ex vivo, not a patient trial
source: PubMed and ClinicalTrials.gov · no exact human trial
What is known about safety?
Human safety data are unavailable. Irritation, sensitization, copper toxicity, pregnancy, interactions, chronic use, injection, and product purity have not been characterized.
source: PubMed and ClinicalTrials.gov · no exact human trial
Is AHK-Cu an approved hair-loss drug?
FDA and ClinicalTrials.gov records contain no approved AHK-Cu hair-loss drug or exact registered intervention trial. Cosmetic ingredient availability is not drug approval.
source: PubMed and ClinicalTrials.gov · no exact human trial
Studies and sources
Human follicle study · ex vivo, not a patient trial
Ex vivo and cell study
Pyo HK et al. Archives of Pharmacal Research, 2007.
AHK-Cu at 10^-12 to 10^-9 molar increased elongation of isolated human scalp follicles and proliferation of cultured dermal papilla cells. The reported reduction in apoptosis was not statistically significant. No person received the compound.
- Participants / model
- Isolated human scalp hair follicles and cultured dermal papilla cells
- Treatment
- Laboratory AHK-Cu exposure
- Study design
- Ex vivo follicle culture and in vitro cell experiment
A living follicle in culture does not establish scalp penetration, cosmetic benefit, or safety in a user.
Read the original sourceCombination study · AHK-Cu not isolated
Human comparative study
Kapoor R et al. Journal of Cosmetic Dermatology, 2020.
The paper evaluated a proprietary multi-factor formulation for hair loss. Any AHK-Cu component was delivered with other ingredients, so the study cannot assign the result to AHK-Cu.
- Participants / model
- People treated for pattern hair loss
- Treatment
- Proprietary multi-ingredient QR678 formulation
- Study design
- Clinical comparison of a combination product
Because QR678 contains multiple factors, any change cannot be attributed to AHK-Cu.
Read the original sourcePubMed and ClinicalTrials.gov · no exact human trial
Literature and registry record set
PubMed and ClinicalTrials.gov records.
The cited records include the ex vivo follicle paper and adjacent combination or coordination-chemistry literature. They contain no published administered-human monotherapy trial or exact ClinicalTrials.gov intervention record for AHK-Cu.
- Study design
- Exact-name and alias coverage
Adjacent copper peptide · delivery caveat
Adjacent-molecule formulation review
Ogórek R et al. Molecules, 2025.
This GHK-Cu review documents the skin-barrier problem for a related hydrophilic copper tripeptide. It does not prove AHK-Cu delivery or efficacy, but it shows why test-tube activity cannot be assumed to survive a topical formulation.
- Study design
- Narrative formulation review of a different copper peptide
The review covers GHK-Cu skin delivery and reports no AHK-Cu efficacy results.
Read the original sourceWhy is AHK-Cu in C tier?
C tier rests on one ex vivo follicle study and cultured-cell findings. PubMed and ClinicalTrials.gov listed no AHK-Cu clinical trial establishing hair-growth efficacy or safety.
how tiers are graded: methodology · every cited source · about reptides.
Research reference, not medical advice. Entries distinguish product labels, study doses and reported protocols. Check the linked source for the product, route and population.