Alfatradiol

Alfatradiol
Clinical data
Trade names	Avicis, Avixis, Ell-Cranell Alpha, Pantostin
Other names	17α-Estradiol; 17-Epiestradiol; MX-4509; Estra-1,3,5(10)-triene-3,17α-diol; β-Estradiol (obsolete, misleading)
AHFS/Drugs.com	International Drug Names
Pregnancy; category	No studies;
Routes of; administration	Topical
Drug class	Estrogen; 5α-Reductase inhibitor
ATC code	None;
Legal status
Legal status	US: ℞-only;
Identifiers
	IUPAC name (8R,9S,13S,14S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol;
CAS Number	57-91-0 ;
PubChem CID	68570;
ChemSpider	61840 ;
UNII	3VQ38D63M7;
ChEBI	CHEBI:17160 ;
ChEMBL	ChEMBL286452 ;
Chemical and physical data
Formula	C18H24O2
Molar mass	272.388 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES OC1CCC3C1(C)CCC(c2cc4)C3CCc2cc4O;
	InChI InChI=1S/C18H24O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h3,5,10,14-17,19-20H,2,4,6-9H2,1H3/t14-,15-,16+,17-,18+/m1/s1 ; Key:VOXZDWNPVJITMN-SFFUCWETSA-N ;
	(verify)

Alfatradiol, also known as 17α-estradiol and sold under the brand names Avicis, Avixis, Ell-Cranell Alpha, and Pantostin, is a weak estrogen and 5α-reductase inhibitor medication which is used topically in the treatment of pattern hair loss (androgenic alopecia or pattern baldness) in men and women. It is a stereoisomer of the endogenous steroid hormone and estrogen 17β-estradiol (or simply estradiol).