If you notice any cloudiness, discoloration, or floating particles, do not use it
2025 Jul 15:S0002-9629(25)01106-1
Its fast-absorbing, lightweight texture leaves a refreshing finish, making it suitable for all skin types and seasons
Increased lipid oxidation causes oxidative stress, increased peroxisome proliferator-activated receptor-gamma expression, and diminished pro-osteogenic Wnt signaling in the skeleton
doi: 10.1016/j.mehy.2004.03.037
If you compress everything above into a single honest verdict, it is this: for skin, the evidence points to topical GHK-Cu as the route with actual human support modest, imperfect, but real while injectable GHK-Cu for skin remains an extrapolation that has not been tested in controlled human trials