MK591(Quiflapon sodium) is a selective and specific 5-Lipoxygenase-activating protein (FLAP) inhibitor.

MK-4074 is a potent, liver-specific, orally active inhibitor of acetyl-CoA carboxylase ACC1 and ACC2 with IC50 of ~3 nM.

MK-4074 is a potent, liver-specific, orally active inhibitor of acetyl-CoA carboxylase ACC1 and ACC2 with IC50 of ~3 nM.

MK-3901 is a potent, selective, orally active P2X3 antagonist with IC50 of 21 nM.

MK-3697 is a third insomnia drug, currently being developed by Merck. MK-3697 is a potent and selective Orexin receptor antagonist with Ki = 0.95 nM.

MK-3281 is a potent and orally bioavailable inhibitor of HCV NS5B polymerase with IC50 of 6 nM.

MK-3207 is a potent and orally bioavailable CGRP receptor antagonist (IC50= 0.12 nM; Ki value= 0.024 nM); highly selective versus human AM1, AM2, CTR, and AMY3.

MK2-IN-1 is a potent, selecitve, non-ATP competitive MAPKAPK2(MK2) inhibitor with IC50 of 0.11 uM.

MK-2894 is a highly potent and selective second generation EP4 antagonist.

MK-2048 is a potent inhibitor of HIV-1 integrase (IN) and IN mutant R263K with IC50 of 2.6 nM and 1.5 nM, respectively.

MK-204 is a potent, selective AKR1B10 inhibitor with IC50 of 80 nM, shows high selective (270-fold) over AKR1B1.

MK-1925 is a selective, orally active, brain-penetrant opioid receptor-like 1 (ORL1.

MK-1832 is a potent, selective Kv1.5 inhibitor with IC50 of 86 nM, exhibits improved selectivity for IKur over IKs (>3000-fold) compares with MK-0448 (70-fold), also exhibits an improved preclinical pharmacokinetic profile..

MK1 is a small molecule inducer of megakaryopoiesis (EC90=750 nM) that induces the differentiation of common myeloid progenitors (CMP) to megakaryocytes, does not adversely affect erythrocyte differentiation.

MK-0974(Telcagepant) is a highly potent, selective, and orally bioavailable CGRP receptor antagonist with Ki values of 0.77 nM and 1.2 nM for human and rhesus CGRP receptors respectively; displays >1500-fold lower affinity for the canine and rat receptors

MK-0812 is chemokine receptor CCR-2 antagonist

MK-0731 is a potent, selective kinesin spindle protein (KSP) inhibitor with IC50 of 2.2 nM, cell EC50 of 5.3 nM.

MK-0674 is a potent, selective, reversible and orally active cathepsin K inhibitor with IC50 of 1 nM.

MK-0448 is a potent, specific I(Kur) current/Kv1.5 channel inhibitor with IC50 of 8.6 nM, potently inhibits IKur in human atrial myocytes with IC50 of 10.8 nM.

MK-0429 is a potent, selective, orally-active nonpeptide αvβ3 integrin inhibitor with IC50 of 0.08 nM in SPAV3 assay.

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-0249 is a novel potent, selective histamine H3 inverse agonist for the treatment of cognitive impairment with schizophrenia..

MJN-228 is a selective ligand for the lipid-binding protein nucleobindin 1 (NUCB1) with IC50 of 3.3 uM (blocks AEA-DA probe labeling of NUCB1).

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.

MIV-711 (MIV711, MV076159) is a potent, selective cathepsin K inhibitor with Ki of 0.98 nM, displays >1300-fold versus the other human cathepsins.

MIV-247 (MIV247) is a potent, selective, orally active inhibitor of cathepsin S with Ki of 2.1 nM (human cathepsin S).

miR544-IN-1 (SID 3712249) is a selective small molecule inhibitor of miR-544 biogenesis.

miR-21 inhibitor 37 is a novel inhibitor of miR-21 function with EC50 of 5.3 uM in HeLa-miR21-Luc assays, displays no inhibition of miR-122.

MIR17PTi is a novel LNA gapmeR antisense oligonucleotide (LNA-ASO), first-in-class inhibitor of pri-mir-17-92.

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.