Mestilbol

Mestilbol
Clinical data
Trade names	Monomestro, Monomestrol
Other names	Monomethylstilbestrol; Diethylstilbestrol monomethyl ether
Drug class	Nonsteroidal estrogen; Estrogen ether
Identifiers
	IUPAC name 4-[(E)-4-(4-methoxyphenyl)hex-3-en-3-yl]phenol;
CAS Number	18839-90-2;
PubChem CID	3032340;
ChemSpider	2297337;
UNII	N44U12UW5N;
ChEBI	CHEBI:34702;
CompTox Dashboard (EPA)	DTXSID90860231 DTXSID7022469, DTXSID90860231 ;
Chemical and physical data
Formula	C19H22O2
Molar mass	282.383 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CCC(=C(CC)C1=CC=C(C=C1)OC)C2=CC=C(C=C2)O;
	InChI InChI=1S/C19H22O2/c1-4-18(14-6-10-16(20)11-7-14)19(5-2)15-8-12-17(21-3)13-9-15/h6-13,20H,4-5H2,1-3H3/b19-18+; Key:CKMDPZMWUZDKAI-VHEBQXMUSA-N;

Mestilbol (brand name Monomestro or Monomestrol), also known as diethylstilbestrol monomethyl ether, is a synthetic nonsteroidal estrogen of the stilbestrol group related to diethylstilbestrol.^[1]^[2]^[3] It was developed by Wallace & Tiernan Company,^[3] patented in 1940,^[4] and introduced for medical use in the 1940s,^[5] but is now no longer marketed. Mestilbol was available both as oral tablets and in oil for intramuscular injection.^[3]^[6] The drug is gradually demethylated in the body into diethylstilbestrol and hence is a prodrug of diethylstilbestrol.^[7] Mestilbol is a highly active estrogen,^[6] although somewhat less so than diethylstilbestrol,^[8] but is longer-lasting in comparison.^[9]