2020 doi: 10.1016/j.scispo.2020.04.005
Answer: GHK-Cu is most often used topically in clinically formulated products or, under medical supervision, as an injectable peptide
Recalls & Warnings July 26, 2013 Safety of Certain Weight Loss and Bodybuilding Supplements Called Into Question On July 25, 2013, USA Today reported that several supplements, including weight loss, body building and sports nutrition supplements, have come under scrutiny after being found to contain illegal ingredients, or were associated with failed drug tests and adverse events
Peptides are short chains of amino acids that act as signaling molecules in the body, as MedlinePlus describes in its overview of peptide hormones
Skin Concerns
References: Pickart, Loren, and Anna Margolina