alpha-MSH TFA (α-MSH TFA, α-MSH Trifluoroacetate, alpha-MSH Trifluoroacetate,α-Melanocyte-stimulating hormone TFA, α-Melanocyte-stimulating hormone Trifluoroacetate) is a 13-amino acid peptide hormone. an endogenous MC4R agonist. alpha-MSH TFA is an endogenous MC3R and MC4R agonist with EC50s of 0.16 nM and 56 nM for hMC3R and hMC4R in Hepa cells, respectively.