Love this write-up Sarah! The timeline you’re describing is consistent with what the collagen synthesis research suggests. GHK-Cu upregulates collagen and glycosaminoglycan production, but connective tissue changes take weeks to accumulate.

On PTD-DBM: yes, it can be combined with GHK-Cu and there’s some logic to it, they work on different pathways (GHK-Cu on collagen/wound healing, PTD-DBM on Wnt signaling for follicle regeneration). Some people alternate AM/PM, some use GHK-Cu for skin and PTD-DBM specifically on the hairline. I’d start them separately so you can attribute any changes accurately.