The copper content of GHK-Cu formulations has been a theoretical safety consideration, given that excessive copper can be toxic - however, the amounts used in cosmetic and research applications are extremely small, the copper is tightly chelated by the peptide (reducing free copper availability), and topical absorption of copper from these products appears minimal and well below levels that would cause systemic copper accumulation or toxicity
J Mol Endocrinol 25 , 141148 (2000)
Healthy glutathione levels slow down the aging process, help your cells function more optimally, reduce inflammation in your body, and so much more
Exploring the Safety and Efficacy of Glutathione Supplementation for Skin Lightening: A Narrative Review Weschawalit, S., et al
CISD2 inhibition overcomes resistance to sulfasalazine-induced ferroptotic cell death in head and neck cancer
J Biol Chem 1999;274:20281-6