AHK-Cu vs. GHK-Cu
Both AHK-Cu and GHK-Cu are copper peptides: short chains of amino acids bound to copper. The difference is in the peptide sequence itself. GHK-Cu is glycyl-L-histidyl-L-lysine copper, while AHK-Cu is alanine-L-histidyl-L-lysine copper. That one amino-acid change may seem small, but it can change how the peptide behaves biologically and where formulators tend to use it.



