This is the lowest-risk route, sits within established cosmetic use, and is supported by the most human data
The deltoid and gluteal muscles are common sites for these injections
While its body of published research is smaller than that of GHK-Cu, ongoing studies continue to expand our understanding of hair follicle signaling, collagen biology, extracellular matrix remodeling, and tissue repair mechanisms
Sepesi B, Weissferdt A, Vaporciyan AA, Futreal A, Karpinets T, Yee C, Haymaker C, Federico L, Forget MA, Lizee G, Talukder A, Roszik J, Tran H, Vasquez M, Prado E, Gehrens C, Parra E, Rodriguez-Canales J, Fujimoto J, Vence L, Roth J, Meraz I, Roarty E, Landry L, Byers L, Swisher SG , William Jr W, Allison S, Fang B, Zhang J, Wagner H, Bogatenkova E, Wistuba II, Heymach JV, Bernatches C, Gibbons D
doi: 10.1513/pats.200708-137mg, 10
The mechanism is not complicated, but it explains almost everything about this side effect