A copper-peptide skin-and-hair stack — GHK-Cu as the workhorse with AHK-Cu as a hair-focused topical add-on.
GHK-Cu is the most-studied copper peptide for skin remodelling — it supports collagen, has antioxidant activity, and is used both topically and (less commonly) injectable. It's the base of any skin-focused stack.
AHK-Cu is a related copper peptide with more of a hair-follicle and microcirculation focus, added topically for those whose primary goal includes hair. Both are well tolerated topically; the injectable route for GHK-Cu carries the usual research-compound caveats and isn't necessary for a cosmetic skin goal.