It is important to note that this concern is entirely theoretical -- no oncological adverse effects have been reported in the limited preclinical studies -- but the biological plausibility is high enough to warrant serious consideration
Li N, Zhao L, Geng X, Liu J, Zhang X, Hu Y, Qi J, Chen H, et al
Thigh The front and outer portions of the thigh provide good subcutaneous tissue
The world's first low molecular weight GHK-Cu topical serum, blended with hyaluronic acid, hydrolyzed collagen and other powerful ingredients, designed to support your skin every single day
In fact, vitamin C can potentially enhance the effectiveness of glutathione
PMID 17961276