 It is completely absorbed from the gastrointestinal tract after oral administration and undergoes extensive first pass metabolism to its active form, 2-hydroxyflutamide, and hydrolysis product, 3-trifluoromethyl-4-nitroaniline.Hydroxyflutamide is a more potent AR antagonist than flutamide "in vivo", with higher binding affinity for the AR.Hydroxyflutamide has an elimination half-life of about 8 hours in humans.