( EC 50 =3 nM). hMC1R agonist 1 shows at least 300-fold selectivity for hMC1R over hMC3R (b>EC 50 =902 nM), hMC4R (b>EC 50 =915 nM), and hMC5R (b>EC 50 =>1000 nM). hMC1R agonist 1 has the potential for the therapeutic intervention of melanocortin family.