What Is AHK-Cu? Copper Tripeptide-3 Structure and Literature

AHK-Cu, also called copper tripeptide-3, is the copper(II) complex of the tripeptide alanyl-histidyl-lysine. It is a synthetic analog of GHK-Cu in which the first residue, glycine, is replaced by alanine. The peptide alone weighs about 354.4 Da; the copper complex is commonly listed as C15H24CuN6O4 at about 415.9 Da with the CAS number 767286-83-9, while its hydrochloride salt is registered separately as 682809-81-0.

How does it relate to GHK-Cu?

GHK-Cu occurs naturally in human plasma and has a large published literature [2]. AHK-Cu was designed as a close analog: the alanine adds a single methyl group to the first residue, while the histidine and lysine that coordinate copper are unchanged. Results reported for one compound should not be assumed for the other.

What does the published literature cover?

The literature on AHK-Cu is small. The most cited study examined the effect of the tripeptide-copper complex on human hair follicle cells in vitro and reported proliferative activity [1]. Beyond that, most published data concerns GHK-Cu, not AHK-Cu specifically, and a 2018 review of GHK-Cu gene expression data did not address AHK-Cu [2].

How is it identified in the laboratory?

AHK-Cu and GHK-Cu differ by 14 Da (one methyl group). Mass spectrometry can distinguish them, but at low resolution the difference is small enough to be ambiguous, so a reference standard is important. The copper complex is blue; solutions of the free peptide without copper are colorless.

Frequently asked questions

Can GHK-Cu literature be applied to AHK-Cu?

Not directly. The two peptides have different primary sequences and may behave differently despite structural similarity.

What CAS number should appear on a certificate of analysis?

767286-83-9 for the free copper complex, or 682809-81-0 for the hydrochloride salt.

Does FLASK list AHK-Cu?

Yes, as AHK-Cu 50 mg, with structure data on the product page.