doi:10.1016/j.peptides.2022.170731
The free apo-peptide binds copper(II) with high affinity through its N-terminal amine, the histidine imidazole nitrogen, and the deprotonated amide nitrogen, forming the GHK-Cu species that figures in much of the published literature
[PubMed] [Google Scholar] 105.PCO-02Safety and Pharmacokinetics Trial NCT02637284
S.MitchellA
Pros : Most effective peptide stack Natural GH production (not suppression) Proven results No PCT needed Can use long-term Research extensively studied Cons : Requires injection (2-3x daily for Ipamorelin) Need to source from reputable suppliers Not FDA-approved Who it's for : People serious about body composition
Animal Production Science 61(1):6471 Tang Y, Han L, Chen X, Xie M, Kong W, Wu Z (2019) Dietary supplementation of probiotic Bacillus subtilis affects antioxidant defenses and immune response in grass carp under Aeromonas hydrophila challenge