Placebo-controlled trial of high-dose Mesterolone treatment of idiopathic male infertility.

The possible effect of Mesterolone (Schering N.V., Brussels, Belgium) (1 alpha-methyl-5-alpha-androstane-17 beta-ol-3-one) on semen quality and fertility of men with idiopathic oligoasthenospermia and/or teratozoospermia has been evaluated in a double-blind trial. The study included 52 patients who were treated during 12 months with either 150 mg/d of Mesterolone or placebo. The overall pregnancy rate was similar in the Mesterolone-treated cases (26%) and in the placebo control cases (48%), although a significant increase in motility and in the proportion of spermatozoa with normal morphology was recorded in the Mesterolone-treated cases. Because similar semen improvement also occurred in the placebo controls, our findings cast doubt on the possible usefulness of high-dose Mesterolone treatment of idiopathic male infertility.