Topical GHK-Cu creams and serums have been studied extensively and they do work for surface-level skin improvement
The most common adverse events are gastrointestinal: nausea (occurring in 12-33% of subjects depending on dose), diarrhea, constipation, and decreased appetite
Cilleros-Holgado P, Gmez-Fernndez D, Piero-Prez R, Romero-Domnguez JM, Reche-Lpez D, Lpez-Cabrera A, lvarez-Crdoba M, Munuera-Cabeza M, et al
Please be informed that Glutathione-containing products are primarily designed for medical purposes and not for cosmetic use.
These studies consistently show: No toxicity, even at high doses Organ-protective and regenerative benefits Absence of tumor formation, cardiovascular damage, or metabolic disruption Despite extensive animal research supporting BPC-157s safety, human safety and pharmacokinetics remain largely unstudied due to its classification as a research chemical. Sikiric, P