Flutamide and 2-hydroxyflutamide have been found in vitro to inhibit CYP17A1 (17α-hydroxylase/17,20-lyase), an enzyme which is required for the biosynthesis of androgens.  In accordance, flutamide has been found to slightly but significantly lower androgen levels in GnRH analogue-treated male prostate cancer patients  and women with polycystic ovary syndrome .  As such, flutamide is a weak inhibitor of androgen biosynthesis.  However, the clinical significance of this action may be limited when flutamide is given without a GnRH analogue to non-castrated men, as the drug markedly elevates testosterone levels into the high normal male range via prevention of AR activation-mediated negative feedback on the hypothalamic–pituitary–gonadal axis in this context. 
In one small scale clinical trial of depressed patients, an improvement of symptoms which included anxiety, lack of drive and desire was observed.  In patients with dysthymia , unipolar , and bipolar depression significant improvement was observed.  In this series of studies, mesterolone lead to a significant decrease in luteinizing hormone and testosterone levels.  In another study, 100 mg mesterolone cipionate was administered twice monthly.  With regards to plasma testosterone levels, there was no difference between the treated versus untreated group, and baseline luteinizing hormone levels were minimally affected.