Suppression of spermatogenesis by testosterone enanthate in Thai men

To investigate the effect of testosterone enanthate on suppression of spermatogenesis in Thai men, 17 normal Thai men were given 200 mg testosterone enanthate weekly by intramuscular injection. During treatment, semen was collected regularly to monitor spermatogenesis. Median times for the first semen sample reaching sperm concentration threshold of 5, 3, 1 and 0 million/ml were 58, 70, 84, and 85, respectively. Subsequently, all men became azoospermic. Among 17 men entering the efficacy phase, 14 (82.3%) achieved consistent azoospermic from the beginning of efficacy phase, the remaining 3 (17.7%) were initially severe oligozoospermic but later became azoospermic. Only one case achieved consistent oligozoospermia but did not achieve azoospermia within 6 months. After stopping injection, sperm first reappeared in the ejaculate of formerly azoospermia men at 73 days. Recovery of sperm output to normal sperm concentration (> 20 million/ml) was achieved by all men at a median time of 3.9 months and recovery to their own baseline in one year after the last injection was established in 13/17 (76.5%) at a median time of 4.9 months, respectively. In conclusion, testosterone enanthate alone is effective in suppression of spermatogenesis for male hormonal contraception due to the high rate of azoospermia induced, which is known to ensure reliable and effective, reversible contraception.