Paulsen, C. AlvinChristensen, Richard B.Matsumoto, Alvin M.Bremner, William J.Bebb, Richard A.Anawalt, Bradley D.2008-10-172008-10-171996-02J Clin Endocrinol Metab. 1996 Feb;81(2):757-62http://hdl.handle.net/1773/4348Studies using high dose testosterone (T) administration in normal men as a male contraceptive have resulted in azoospermia rates of only 50-70%. Previous studies of T and progestogen combinations have shown comparable rates of azoospermia, but have been uncontrolled or used T in doses less than that associated with maximal suppression of sperm production. We conducted a randomized, placebo-controlled, single blind trial comparing 6 months of T enanthate administration (100 mg, im, weekly) with the same dose of T enanthate in conjunction with the progestogen levonorgestrel (LNG; 500 micrograms, orally, daily) in 36 normal men, aged 20-42 yr (n = 18 in each group). The primary end points were induction of azoospermia or severe oligospermia (< 3 million sperm/mL). The combination of T plus LNG was much more effective in suppressing sperm production than T alone. Sixty-seven percent of the T plus LNG group (12 of 18) and 33% of the T alone group (6 of 18) achieved azoospermia by 6 months (P = 0.06). Severe oligospermia or azoospermia developed in 94% of the T plus LNG (17 of 18) group compared to 61% of the T alone group (11 of 18; P < 0.05). T plus LNG also suppressed sperm production more rapidly than T alone. Time to azoospermia was 9.9 +/- 1.0 vs. 15.3 +/- 1.9 weeks in the T plus LNG and T alone groups, respectively (mean +/- SEM; P < 0.05). Serum high density lipoprotein cholesterol decreased 21.7 +/- 3.6% in men given T plus LNG (P < 0.05), compared to only a 1.8 +/- 3.8% decrease in men in the T alone group. Average weight gain was 5.3 +/- 0.8 kg in the T plus LNG group and 2.3 +/- 0.9 kg in the T alone group (P < 0.05). Acne and increase in hemoglobin were similar in the two groups. We conclude that combination hormonal therapy with T plus a progestogen might offer a reversible male contraceptive approach with a more rapid onset of action and more reliable induction of both azoospermia and severe oligospermia than T alone.en-USmale contraception5-alpha reductase inhibitorsandrologyreifenstein's syndromegonadotropinscolchicinespermatogenesistestosteroneklinefelter's syndromeFollicle Stimulating Hormone, bloodWeight GainContraceptive Agents, Male, pharmacologyLevonorgestrel, administration & dosage, adverse effects, pharmacologyLuteinizing Hormone, bloodHumansResearch Support, U.S. Gov't, Non-P.H.S.MalePlacebosSperm CountLipoproteins, HDL Cholesterol, bloodAdultResearch Support, Non-U.S. Gov'tTestosterone, administration & dosage, adverse effects, pharmacologySpermatogenesis, drug effectsResearch Support, U.S. Gov't, P.H.S.Article