A non-steroidal antiandrogen; binds to the androgen receptor (Kd = 1.8, 1.1, 5.6, 1.3, and 1.4 nM for human, rat, mouse, hamster prostate, and hamster flank organ receptors, respectively); reduces size of the flank organ without affecting sex organs in hamsters topically from 1-100 μg/animal; no effect on sex organ weight in intact rats up to 1 mg/animal; induces hair regrowth in the bald frontal scalps of postpubertal stumptailed macaques at 5% v/v, topical