Cingestol

Cingestol
Clinical data
Trade names	Lutisan
Other names	19-Nor-17α-pregn-5-en-20-yn-17β-ol; O.V. 28
Routes of; administration	Oral
Identifiers
	IUPAC name (8R,9S,10R,13S,14S,17R)-17-ethynyl-13-methyl-2,3,4,7,8,9,10,11,12,14,15,16-dodecahydro-1H-cyclopenta[a]phenanthren-17-ol;
CAS Number	16915-71-2;
PubChem CID	11954351;
ChemSpider	10128646;
UNII	VLJ9702J11;
CompTox Dashboard (EPA)	DTXSID70168666 ;
ECHA InfoCard	100.037.225
Chemical and physical data
Formula	C20H28O
Molar mass	284.443 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C[C@]12CC[C@H]3[C@@H](CC=C4CCCC[C@H]34)[C@@H]1CC[C@@]2(O)C#C;
	InChI InChI=1S/C20H28O/c1-3-20(21)13-11-18-17-9-8-14-6-4-5-7-15(14)16(17)10-12-19(18,20)2/h1,8,15-18,21H,4-7,9-13H2,2H3/t15-,16+,17+,18-,19-,20-/m0/s1; Key:HSYWFJBHXIUUCZ-XGXHKTLJSA-N;

Cingestol (INN, USAN) (former tentative brand name Lutisan), also known as 17α-ethynylestr-5-en-17β-ol, is a steroidal progestin of the 19-nortestosterone group that was never marketed. It was synthesized in 1969 and was developed in the 1970s by Organon as a low-dose, progestogen-only contraceptive, but in 1984, was still described as "under investigation". The drug is an isomer of lynestrenol with the double bond between C5 and C6.