AHK-CU

A single amino acid separates AHK-Cu from its well-known relative GHK-Cu: alanine sits in the first position instead of glycine, while the rest, histidine and lysine with a bound copper ion, is identical. Small as the difference is, in preclinical work it shifts the activity profile.

The focus is on hair. Cell culture studies connect AHK-Cu with two observations:

• The growth phase of the hair follicle (anagen) lasts longer.
• Cells of the dermal papilla, which nourish the follicle, undergo programmed cell death less often.

Some mechanisms are shared with GHK-Cu, such as the regulation of metalloproteinases and the influence on microcirculation. The available data, however, also point to effects of its own on follicle biology.

Chemically, AHK-Cu behaves like other copper tripeptides: in solution it appears bluish, and the copper is tightly bound, which keeps the compound stable under physiological conditions. As a small tripeptide it is broken down quickly, though, and accordingly has a short half-life. In research it is examined mainly topically, in preclinical models also subcutaneously.

If you search the literature on AHK-Cu, you will find far less than on GHK-Cu. Much of what is said about the molecule is carried over from its relative; specific work is essentially confined to cell culture and hair follicles.

AHK-Cu shares the mild profile of GHK-Cu, best documented for application to the skin. Its own evidence base is narrow and consists mostly of cell culture work; long-term human studies do not exist.

• Injection site: redness, a feeling of pressure or a brief irritation with subcutaneous administration.
• Copper: the copper complex can slightly intensify local irritation compared with copper-free peptide solutions. For very high or very frequent amounts the literature debates a theoretical danger of copper accumulation.
• Short half-life: the rapid breakdown of the tripeptide means short windows of activity but does not change the mild profile.

This summary is no substitute for medical advice.

• The effect of tripeptide-copper complex on human hair growth in vitro - human hair follicles ex vivo grew longer under AHK-Cu already at picomolar to nanomolar concentrations, dermal papilla cells divided more often, the Bcl-2 to Bax ratio rose and cleaved caspase-3 fell.
• GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration - review of the related GHK-Cu, not of AHK-Cu: collagen and glycosaminoglycan formation, attraction of immune and endothelial cells, skin and follicle effects in animal models.
• Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data - second review of the relative GHK-Cu with gene expression data on tissue repair and fibroblasts; AHK-Cu does not appear in the abstract.