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.
PIP: To assess the effect of testosterone enanthate on the suppression of spermatogenesis, 17 healthy Thai men received weekly intramuscular injections (200 mg) of the hormone, and spermatogenesis was monitored during the suppression, efficacy, and recovery phases. All subjects reached the oligozoospermic threshold during the suppression phase. Median times for the first semen sample to reach sperm concentrations of 5, 3, 1, and 0 million/ml were 58, 70, 84, and 85 days, respectively, and both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were suppressed below the detection limit. 14 men (82.3%) were consistently azoospermic from the onset of the efficacy phase, while the 3 initially oligozoospermic subjects achieved azoospermia. Variations in rates of azoospermia were unrelated to age, body size, initial testicular volume, or baseline sperm concentrations. There were 2 discontinuations during this phase (due to abnormal liver function tests in 1 case and weight gain and hypertension in another). After injections were stopped, sperm first reappeared in the ejaculate after a median interval of 73 days and normal sperm concentrations were recorded at 3.9 months. Plasma FSH and LH levels rebounded after a median time of 3 months. These findings confirm the potential of testosterone injection as a safe, reversible, effective method of male hormonal contraception.