Effects of testosterone enanthate in normal men: experience from a multicenter contraceptive efficacy study. World Health Organization Task Force on Methods for the Regulation of Male Fertility.

ABSTRACT

PIP: At 10 centers in 7 countries, researchers conducted a clinical trial of weekly intramuscular injections of 200 mg testosterone (T) enanthate in 271 healthy fertile men, 21-45 years old, to evaluate the secondary impact of this prototype male contraceptive regimen on various physical, metabolic, and behavioral variables. They also focused on the differences between Chinese men and non-Chinese men as well as their similarities. At baseline, Chinese men were shorter, weighed less, and had lower levels of hemoglobin, plasma lipids, and liver enzymes than non-Chinese men (p 0.05). The overall leading side effects were acne (80), fatigue (22), painful injections (15), and weight gain (12). 24 men, all of whom were non-Chinese men, experienced excessive development of the male mammary glands (gynecomastia). Nine men (1 Chinese, 8 non-Chinese) had prostate problems. No man discontinued T enanthate injections for gynecomastia or prostate problems, however. T enanthate contributed to an increased body weight (by 5% at 360 days) and increased levels of hemoglobin (by 7.6% at 360 days) and creatinine while it contributed to a decrease in testicular volume (by 26.2% at 360 days) and in urea level. T enanthate appeared to have no effect on plasma triglyceride, cholesterol, and low density lipoprotein (HDL) cholesterol. It was associated with a decrease of 14-18% in HDL-cholesterol in non-Chinese men but it had no effect on HDL-cholesterol in Chinese men. T enanthate increased liver transaminase by 36-51% in Chinese men but it had no effect on these enzymes in non-Chinese men. Regardless of length of exposure to T enanthate, the T enanthate-induced changes were reversible within 6 months. These findings suggest that T enanthate produced significant but reversible metabolic and physical effects that differed between Chinese and non-Chinese men. These effects are a result of the relatively high peak levels and fluctuations of plasma T produced by the weekly injections rather than an inherent feature of hormonal male contraception.