ACTH (1-39) is agonist of melanocortin receptor 2 (MC2R) with an EC50 of 57 pM in HeLa cells expressing the mouse receptor.

SHU 9119 is a potent human melanocortin 3 and 4 receptors (MC3/4R) antagonist and a partial MC5R agonist; with IC50 values of 0.23, 0.06, and 0.09 nM for human MC3R, MC4R and MC5R, respectively. It induces cAMP formation in HEK293 cells expressing human MC1R (EC50 = 1.11 nM), but inhibits cAMP formation in cells expressing human MC4R.

Melanotan I, a synthetic analog of α-MSH, is an agonist of melanocortin receptors with Ki values of 0.085, 0.4, 3.8 and 5.1 nM for MC1, MC3, MC4 and MC5 receptors respectively.

Melanotan II, an analog of α-melanocyte stimulating hormone, is agonist of MC3-R/MC4-R melanocortin that induces melanogenesis and thus increases skin pigmentation.

Bremelanotide acetate is a melanocortin agonist.

α-MSH is endogenous agonist of melanocortin receptor with Ki values of 0.12, 31, 660 and 5700 nM for MC1, MC3, MC4 and MC5 receptors respectively.

THIQ is the first selective agonist of the melanocortin-4 receptor (MC4R), with high affinity and potency for hMC4R (IC50=1.2 nM, EC50=2.1 nM) and rMC4R (IC50=0.6 nM, EC50=2.9 nM). THIQ maintains low potency at MC1R, MC3R and MC5R. THIQ plays a role in eliciting erectile activity in rodents. THIQ acts as a pharmacoperone of the MC4R rescuing the cell surface expression and signaling of some intracellularly retained MC4R mutants .