Skip to content
Educational information only. Not medical advice. We sell nothing and take no affiliate money.
By /
Peptide (copper complex)Lab onlyNot FDA approved

AHK-Cu

Alanyl histidyl lysine copper

Last reviewed October 27, 2026 · 8 sources · Written for general readers · Compare with another compound →

The bottom line

AHK-Cu is a copper peptide closely related to GHK-Cu.[1][2] The only peer reviewed research we could verify is a 2007 lab study on hair follicles and scalp cells grown in dishes; a 1990s company patent also reported hair growth in mice, but that was never published as a journal study, and no human trial exists.[1][3] Skin, collagen and anti aging claims borrow from GHK-Cu research, and products that claim to regrow hair are legally drugs, not cosmetics.[2][4]

Where the evidence stands

What it is

AHK-Cu is a peptide made of three amino acids, alanine, histidine and lysine, bound to copper.[1] It differs from the better known GHK-Cu by one amino acid.[1][2]

Interest in AHK-Cu for hair goes back to a patent filed in 1994 by a copper peptide company, which listed AHK copper among complexes claimed to stimulate hair growth.[3] The main journal study came later, in 2007, and tested it on human hair follicles kept alive in the lab.[1]

A major review of cosmetic peptides covers GHK-Cu in detail but does not mention AHK-Cu at all.[2]

In the US, a product's legal category depends on its claims. A cosmetic can be sold without FDA approval, but a product that claims to restore hair growth is treated as a drug.[4] AHK-Cu does not appear on FDA's compounding category lists.[5]

Name
AHK-Cu (Alanyl histidyl lysine copper)
Other names
copper tripeptide AHK, L-alanyl-L-histidyl-L-lysine copper
Type
Peptide (copper complex)
Sequence
AHK

What it does in the body

AHK-Cu does not occur naturally as a known hormone or signal in the body. It is a lab made copper peptide, and the proposed main action is on dermal papilla cells, the small cluster of cells at the base of each hair follicle that steers hair growth.[1]

This is the biology, area by area. A change measured in the body, like a higher blood level, does not always mean a person feels a benefit. The claims check below covers that.

Hair follicles

Lab finding

In human scalp follicles kept alive in a dish, AHK-Cu made hair shafts grow longer, and it made dermal papilla cells multiply.[1] It shifted proteins that control cell death toward survival, but the drop in dying cells was not statistically significant.[1]

Hair growth in mice

Seen in animals

A 1996 company patent reported that injecting copper peptide complexes into the skin of mice started hair growth within days, and that AHK copper rubbed on mouse skin worked better than a similar complex with a different last amino acid.[3] These were company experiments described in a patent, not peer reviewed studies, and the details cannot be checked independently.

Skin and collagen

Lab finding

No study has measured what AHK-Cu does to skin collagen. The closely related GHK-Cu raised collagen production in skin cells grown in the lab, which is where most skin claims for AHK-Cu come from.[6][2] That finding cannot simply be assumed for AHK-Cu, which is a different molecule.

How it works

The proposed idea centers on dermal papilla cells, a small cluster of cells at the base of each hair follicle that helps control hair growth.[1]

  • In lab dishes, AHK-Cu made dermal papilla cells multiply and made isolated hair follicles grow longer.[1]
  • It shifted proteins that control cell death toward cell survival, which the authors think could help follicles keep growing.[1]
  • The drop in the number of dying cells was not statistically significant.[1]

This is one lab study plus unpublished patent experiments, and no one has shown the same effect in people.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

No peer reviewed animal studies, only patent reports

  • The main published study used human hair follicles and cells grown in the lab, not live animals.[1]
  • In that study, follicles treated with AHK-Cu grew longer than untreated follicles, and dermal papilla cells multiplied more. The fall in dying cells did not reach statistical significance.[1]
  • A 1996 patent reported that copper peptide complexes injected into the skin of C3H mice started hair growth, with the biggest effect about four weeks after injection.[3]
  • The patent also reported that AHK copper put on the skin worked better than a related complex, and that AHK copper injections kept hair around the injection site in a chemotherapy experiment.[3]

Limit: Patent experiments are not peer reviewed, and without independent animal or human studies there is no way to judge real world benefit or safety.

Human studies

No human trials

  • We found no published human trials of AHK-Cu for hair or skin. The key study grew hair follicles in a lab dish, and the patent describes no human tests, so no person has been measured using it.[1][3]

Limit: Growing a follicle in a dish does not show that a serum or injection will grow hair on a person's scalp, and nothing is known about side effects in people.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Regrows hair and thickens thinning hair

Only in animals

In a 2007 lab study, AHK-Cu made human hair follicles kept alive in a dish grow longer and made dermal papilla cells multiply.[1] A 1990s company patent reported hair growth in mice after copper peptides were injected or applied, but this was never published as a journal study.[3] No study has tested it in people with hair loss.

Prevents hair loss from chemotherapy

Only in animals

The same patent described an experiment in which AHK copper injections kept hair around the injection site during chemotherapy in animals.[3] It is not clear from the patent how many animals were used, and no journal study or human trial has tested this.

Boosts collagen and firms skin

Not tested

We found no study of AHK-Cu on skin collagen, in cells, animals or people. The only published AHK-Cu journal study looked at hair follicles.[1] Collagen claims appear to be borrowed from lab research on the related peptide GHK-Cu.[6][2]

Reverses skin aging

Not tested

No study has tested AHK-Cu for wrinkles or other signs of skin aging. A review of anti aging cosmetic peptides covers GHK-Cu but not AHK-Cu.[2]

Speeds wound healing

Not tested

We found no wound healing study of AHK-Cu. The 2007 study measured only hair follicle growth and cell survival in dishes.[1]

Known risks and side effects

  • No human safety data. Because the only studies were done in the lab or described in a patent, side effects and long term safety in people are unknown.[1][3]
  • Hair growth claims. Products that promise hair regrowth are legally drugs that need FDA approval, so that claim on a cosmetic is a warning sign.[4]
  • Unregulated vials. AHK-Cu is not on FDA's compounding category lists, so vials sold online have had no FDA review of purity or sterility.[5]
  • Injected copper peptides raise immune concerns. For the related peptide GHK-Cu, FDA warned that injected forms may cause immune reactions and have limited human safety data.[7]
  • Cosmetic data often unpublished. Many cosmetic peptide studies are small and never published in scientific journals.[2]

Regulatory status

Today: AHK-Cu does not appear on FDA's compounding category lists.[5] Cosmetics need no FDA approval before sale, but a product that claims to restore hair growth is regulated as a drug.[4] It is not named on WADA's 2027 Prohibited List.[8]

  1. A US patent was issued claiming copper peptide complexes, including AHK copper, for stimulating hair growth. The patent has since expired.[3]

Sources

  1. Pyo HK, Yoo HG, Won CH, et al. The effect of tripeptide-copper complex on human hair growth in vitro. Arch Pharm Res. 2007;30(7):834-839. PMID 17703734
  2. Schagen SK. Topical Peptide Treatments with Effective Anti-Aging Results. Cosmetics. 2017;4(2):16. DOI 10.3390/cosmetics4020016
  3. Pallenberg AJ, Patt LM, Trachy RE (ProCyte Corp). Stimulation of hair growth by peptide copper complexes. US Patent 5,538,945. Filed June 17, 1994; issued July 23, 1996. US Patent 5538945
  4. US Food and Drug Administration. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?). FDA
  5. US Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (category lists). Updated May 14, 2026. FDA category list
  6. Maquart FX, Pickart L, Laurent M, Gillery P, Monboisse JC, Borel JP. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. FEBS Lett. 1988;238(2):343-346. DOI 10.1016/0014-5793(88)80509-x
  7. US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Content current as of April 22, 2026. FDA
  8. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2027. In force January 1, 2027. WADA 2027 List
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

Found an error or a newer study? We correct pages fast.

Report a correction →
Scroll to Top