Hydroxyflutamide (developmental code SCH-16423; also known as 2-hydroxyflutamide, HF, and OHF) is a nonsteroidal antiandrogen (NSAA) and the major active metabolite of flutamide, which is considered to be a prodrug of hydroxyflutamide as the active form. It has been reported to possess an IC50 of 700 nM for the androgen receptor (AR), which is about 4-fold less than that of bicalutamide.

vte Affinities
CompoundRBATooltip Relative binding affinity
Metribolone100
Dihydrotestosterone85
Cyproterone acetate7.8
Bicalutamide1.4
Nilutamide0.9
Hydroxyflutamide0.57
Flutamide<0.0057
Notes:
vte Relative affinities of first-generation nonsteroidal antiandrogens for the androgen receptor
SpeciesIC50Tooltip Half maximal inhibitory concentration (nM)RBATooltip Relative binding affinity (ratio)
Bicalutamide2-HydroxyflutamideNilutamideBica / 2-OH-fluBica / niluRef
Rat190700ND4.0ND
Rat~400~900~9002.32.3
RatNDNDND3.3ND
Rata35954565186201.35.2
Human~300~700~5002.51.6
Human~100~300ND~3.0ND
Humana2490234553001.02.1
Footnotes: a = Controversial data. Sources: See template.
vte Relative potencies of selected antiandrogens
AntiandrogenRelative potency
Bicalutamide4.3
Hydroxyflutamide3.5
Flutamide3.3
Cyproterone acetate1.0
Zanoterone0.4
Description: Relative potencies of orally administered antiandrogens in antagonizing 0.8 to 1.0 mg/kg s.c.Tooltip subcutaneous injection testosterone propionate-induced ventral prostate weight increase in castrated immature male rats. Higher values mean greater potency. Sources: See template.