LY344864 is a selective receptor agonist with an affinity of 6 nM (Ki) at the recently cloned 5-HT1F receptor.

LY354740 is an agonist of the group II metabotropic glutamate receptor (mGluR) subtypes mGluR2 and mGluR3 (Kis = 99 and 94 nM, respectively).

LY404039 is an inhibitor for mGluR1(Ki=149 nM) and mGluR2(Ki= 92 nM), which can also inhibit dopamine receptor.

macitentan (Actelion-1, ACT-064992) is an orally active, non-peptide dual endothelin (ET)A/B receptor antagonist with IC50 of 0.5 nM/391 nM.

Maropitant is a neurokinin (NK1) receptor antagonist.

Mavoglurant (AFQ056) is an experimental drug candidate for the treatment of fragile X syndrome.It exerts its effect as an antagonist of the metabotropic glutamate receptor 5 (mGLU5).

MDK-5220(Orexin-2 receptor agonist) is the first selective nonpeptidic orexin 2 receptor (OX2R) agonist (OX2R EC50 = 0.023 μM, Emax = 98%; OX1R EC50 = 1.616 μM, Emax = 100%)

Meclizine is a histamine H1 receptor antagonist used to treat nausea and motion sickness.

Medetomidine hydrochloride is a potent and highly selective α2-AR adrenoceptor agonist (Ki values are 1.08 and 1750 nM for α2- and α1-adrenoceptors respectively). Shows greater selectivity over α1-adrenoceptors than clonidine and UK 14,304 (1620-, 220- an

Dersimelagon, also known as MT-7117 and WHO 10832, is a novel, orally-administered, small molecule, selective melanocortin-1 receptor (MC1R) agonist that increases skin melanin without sun exposure and is being developed to increase light tolerance in EPP/XLP patients. Dersimelagon significantly boosted sunlight tolerance in patients with erythropoietic protoporphyria in a multicenter, phase 2, randomized trial.

Meptazinol Hcl(WY-22811 Hcl) is a unique centrally active opioid analgesic.

Mequitazine is a potent, nonsedative and long-acting histamine H1 antagonist.

Methylnaltrexone Bromide is a pheriphally-acting μ-opioid antagonist that acts on the gastrointestinal tract to decrease opioid-induced constipation.

Metoprolol is a cardioselective β1-adrenergic blocking agent.

MF498 is a novel and selective E prostanoid receptor 4 (EP4) inhibitor, relieves joint inflammation and pain in rodent models of rheumatoid and osteoarthritis.

Minesapride (DSP-6952) is a novel potent, selective, orally active 5-HT4 receptor partial agonist with Ki of 50-100 nM for human 5-HT4a/4b/4c.

Mirabegron is a selective β3-adrenoceptor agonist with EC50 of 22.4 nM.

Mizolastine is a histamine H1-receptor antagonist with IC50 of 47 nM used in the treatment of hay fever (seasonal allergic rhinitis), hives and other allergic reactions.

MK 0524 is a potent, selective DP1 receptor antagonist with Ki values of 0.57 nM and 0.75 µM for the DP1 and DP2 receptors, respectively.

MK-0354 is a partial agonist of GPR109a receptor, for hGPR109a/ mGPR109a with EC50 of 1.65/1.08 μM, showed no activation of GPR109b.

MK-0557 is a highly selective, orally administered neuropeptide NPY5R antagonist, could limit weight regain after very-low-calorie diet (VLCD)-induced weight loss.

MK-0812 is chemokine receptor CCR-2 antagonist