We plan to administer combined spironolactone and testolactone treatment-spironolactone to inhibit the action of androgen, and testolactone to block the formation of estrogen. The goal of this treatment is to delay sexual maturation and to prevent early closure of the epiphyses and adult short stature. These goals are being partially met with spironolactone and we postulate that the addition of testolactone will improve response by slowing bone growth and preventing gynecomastia. Preliminary results using this regimen demonstrate that blockade of both androgen action and estrogen synthesis is an effective treatment for familial male precocious puberty. Throughout the therapy, patients will receive frequent clinical, hormonal, and toxicological monitoring.