Direct conversion from long‐acting testosterone replacement therapy to Natesto allows for spermatogenesis resumption: Proof of concept

Long‐acting testosterone replacement therapy (TRT) suppresses spermatogenesis. A short‐acting TRT, Natesto, maintains spermatogenesis in some men. This study evaluated hormonal and semen parameters converting men from long‐acting TRT to Natesto. Baseline hormones, again on long‐acting TRT and 1 month after converting to Natesto, as well as semen parameters 3 months after converting to Natesto were assessed. Twenty‐seven men were directly converted from long‐acting forms of TRT to Natesto. Mean duration on long‐acting TRT was 24.3 ± 19 months. Testosterone levels were similar on long‐acting forms of TRT and Natesto, however; E2 levels were significantly lower on Natesto. Ten men had semen analyses demonstrating azoospermia while on long‐acting TRT, the remainder were presumed to be azoospermic or severely oligospermic which has been well established as an effect of long‐acting TRT. All 27 men had resumption of spermatogenesis with a mean sperm concentration of 50.7 million/ml after converting to Natesto, considered within the fertile range. One couple achieved a pregnancy 4 months after converting to Natesto. Hypogonadal men on long‐acting TRT interested in resumption of spermatogenesis may convert directly to Natesto for an opportunity to do so while remaining on a form of TRT and achieving lower E2 levels.