ghk-cu upregulates col1a1 Copper Peptide 2026 Review: Benefits, Mechanisms, Safety 89030-95-5 GHK-Cu Gly-His-Lys-Cu Copper Tripeptide-1;
Description
Table S5)

Purity Standards: Target suppliers offering 98% or higher purity, with 99%+ being ideal

Wu Y-L, Smit EF, Bauer TM

Injection site irritation may increase slightly since you are adding a daily injection to your routine, but site rotation prevents this from becoming an issue
The right formula depends on your skin, your goals, and what else you are already using
