25 vitamin c glutathione clinical serum Paula's Choice 25% + This clinical Paula's Choice Vitamin C Glutathione

INGREDIENTS: Deionized Water, Lecithin Phospholipids, L-Glutathione, Alcohol (ethanol), Xanthan Gum, Potassium Hydroxide (for pH adjustment)

Avoid use of hydroxy acids at the same time as GHK products (use at opposite end of the day)

Mechanism Summary

Nature Scientific Reports 2016 comparative study showed GHK-Cu produced no cytotoxicity to human keratinocytes at concentrations up to 5,800 M over 72 hours and did not induce inflammatory biomarkers unlike other copper compounds

PMID 7453802

You'll see better results from NAD+ when you get multiple treatments, and many people notice improvements after finishing a series of sessions