A placebo-controlled, randomized clinical trial using testosterone undecanoate with injectable norethisterone enanthate: effect on anthropometric, metabolic and biochemical parameters

Testosterone administered alone or in combination with progestogens in male contraception induces reversible oligo-azoospermia, but its effects on body composition and metabolism are less known. We analysed anthropometric and metabolic parameters in five groups of 10 males: four receiving testosterone undecanoate (TU: 1000 mg) plus norethisterone enanthate (NETE: 200 mg) at different intervals (every 8 weeks: NETE-8; every 12 weeks: NETE-12; every 6 weeks for 12 weeks and then every 12 weeks: NETE-6/12; every 6 weeks for 12 weeks and then TU plus placebo every 12 weeks: NETE-6/12/0) and one placebo (NETE-0/0) for a total of 48 weeks. Body mass index (BMI) and waist circumference did not change in any groups except for the NETE-8 in which BMI increased significantly (p = 0.02) at the end of the treatment period. Lean body mass (MAMC or AMA) increased significantly in the highest hormonal dose groups (p = 0.04, NETE-6/12; p = 0.004, NETE-8). No differences were observed in glucose levels, insulin sensitivity index and lipid profile as well as in biochemical and cell count parameters in any groups. In conclusion, NETE and TU for 48 weeks were not accompanied by any metabolic changes and any adverse effects. The weight gain of the highest NETE plus TU dosage was mainly because of gain in muscle mass.