peptídeo ghk cu GHK-Cu 50mg Copper Peptide GHK-Cu - Peptide for Collagen,
Description
Unknown long-term profile: Human safety data for this blend is limited, so caution and monitoring are advised

This helps avoid bad side effects

Styling holds better

doi: 10.1016/0960-0760(94)90022-1

If you want the biology the literature predicts, you need a delivery method that bypasses the stratum corneum