Fertilysin

Fertilysin (WIN 18446) is an experimental drug that was studied as a male contraceptive, but was never marketed. It interferes with testicular production of retinoic acid,^[1] which is necessary for spermatogenesis. In studies in male animals including rodents, wolves, cats, and shrews, fertilysin was found to be a safe, effective, and reversible oral contraceptive.^[2][3] However, the side effects observed in human clinical trials preclude its use in men.^[4]

Fertilysin

Clinical data
Other names	WIN 18446
Identifiers
IUPAC name 2,2-Dichloro-N-[8-[(2,2-dichloroacetyl)amino]octyl]acetamide
CAS Number	1477-57-2
PubChem CID	15134
ChemSpider	14405
UNII	3F56RA64JN
ChEBI	CHEBI:90441
ChEMBL	ChEMBL3276621
CompTox Dashboard (EPA)	DTXSID80163783
ECHA InfoCard	100.014.576
Chemical and physical data
Formula	C12H20Cl4N2O2
Molar mass	366.10 g·mol−1
3D model (JSmol)	Interactive image
SMILES ClC(C(NCCCCCCCCNC(C(Cl)Cl)=O)=O)Cl
InChI InChI=1S/C12H20Cl4N2O2/c13-9(14)11(19)17-7-5-3-1-2-4-6-8-18-12(20)10(15)16/h9-10H,1-8H2,(H,17,19)(H,18,20) Key:FAOMZVDZARKPFJ-UHFFFAOYSA-N

Fertilysin was originally studied in the 1950s for its potential amebicidal effects.^[4][5][6] When the anti-spermatogenesis effects were observed in animal studies, the focus of the research turned towards its potential use as a contraceptive. Fertilysin is an inhibitor of aldehyde dehydrogenase 1a2, a member of the aldehyde dehydrogenase family of enzymes. Inhibition of this enzyme blocks the production of retinoic acid which prevents the production of sperm. Because aldehyde dehydrogenases are also involved in the metabolism of ethanol, fertilysin has side effects similar to the action of disulfiram (Antabuse).^[3] Fertilysin may also have teratogenic effects.^[7]