GHK-Cu + AHK-Cu Hair Serum

Two tripeptides, one coordination motif

GHK and AHK differ only at the first residue — glycine versus alanine — and both rely on the His-Lys pair for copper binding. The imidazole nitrogen of histidine, the terminal amine and backbone nitrogens together form the square-planar Cu(II) site, and the resulting complex has an affinity comparable to that of serum albumin's copper-transport site. That similarity is why GHK-Cu is often discussed as a physiological copper carrier rather than simply a copper salt in peptide clothing.

Follicle research

Why formulation matters here

• Copper coordination is pH sensitive; strongly acidic conditions dissociate the complex
• Reducing agents such as ascorbic acid and thiol compounds can reduce Cu(II) and disrupt the peptide complex
• Chelators including EDTA compete for copper and strip it from the tripeptide
• Free copper ions behave very differently from the coordinated complex in cell assays
• Colour loss is a practical, if rough, in-bottle indicator that the active has changed

Study design notes

Keep the bottle upright, tightly closed and refrigerated between uses, shielded from prolonged light. Dispense with the dropper into a clean vessel rather than touching the tip to surfaces, and never return unused liquid to the bottle — contamination shortens the usable life of an aqueous leave-on base. Measure volumes rather than counting drops when a protocol needs a defined amount per unit area. Check the colour before each use: fading from blue toward colourless or a green-brown cast suggests copper coordination has been disturbed, and the material should be retired rather than used in a comparison. Avoid contact with reducing agents, chelators and strongly acidic media.