They let scientists know exactly how much peptide reached the body, which makes it possible to measure real dose-response effects and study what happens in deeper tissues, something a topical cream simply cannot do. How GHK-Cu Influences Gene Expression Research suggests this little peptide can influence the activity of around 4,000 human genes, nudging aged or stressed cells back toward patterns that look more like healthy, younger tissue. That's an unusually wide effect for such a small molecule
Taking more glutathione shouldn't hurt, but you'd be spending money and effort on a health pursuit you dont need to follow
Neuropharmacology 134:178188
Citation: Pickart L, Vasquez-Soltero JM, Margolina A
Yamamoto S, Deguchi K, Onuma M, Numata N, Sakai Y