The best choice depends on the main goal, and in many cases a thoughtful mix of both molecules wins
GHRP-6 peptide was the first synthetic growth hormone-releasing peptide developed and remains one of the most extensively characterized GHS-R1a agonists in the published research literature
However, these days companies realise they need much more intelligent drugs to make them more specific with fewer side effects
Thomas GE, Egan G, Garcia Prat L, Nachmias B, Chin JM, Hoff FW, Kaufmann K, Hurren R, Gronda M, MacLean N, Wang X, Voisin V, Botham A, Arruda A, Minden MD, Bader GD, Kornblau SM , Dick JE, Schimmer AD
99% Purity Standard VivePeptides GHK-Cu consistently meets or exceeds 99% purity as verified by HPLC analysis