pf-00446687 pf-00446687 pf-00446687 is a drug developed by pfizer for the treatment of erectile dysfunction, which is a non-peptide agonist selective for the melanocortin receptor subtype mc4. it was found to be active in preliminary human trials, with the 200mg dose being of similar effectiveness to 100mg sildenafil, though lower doses were ineffective. pf-00446687identifiers iupac name (3r,4r,5s)-1-(carbonyl)-3,5-dimethyl-4-phenylpiperidin-4-ol cas number862281-92-3 ypubchem cid11328898chemspider24669573unii63p236z73ichemical and physical dataformulac28h36f2n2o2molar mass470.593 g·mol−13d model (jsmol)interactive image smiles c1cn(c(1(c2ccccc2)o)c)c(=o)3cn(c3c4ccc(cc4f)f)c(c)(c)c inchi inchi=1s/c28h36f2n2o2/c1-18-14-31(15-19(2)28(18,34)20-9-7-6-8-10-20)26(33)24-17-32(27(3,4)5)16-23(24)22-12-11-21(29)13-25(22)30/h6-13,18-19,23-24,34h,14-17h2,1-5h3/t18-,19+,23-,24+,28-/m0/s1key:whpjoaupizdjnx-aggguqdcsa-n while it is unclear whether pf-00446687 itself will be potent and effective enough to be developed for medical use, it has demonstrated that selectively targeting the mc4 subtype can produce similar aphrodisiac effects to older non-selective peptide-based melanocortin receptor agonists like melanotan ii and bremelanotide, without the side effects caused by action at the other melanocortin receptor subtypes.