Efficacy and Safety of an Injectable Combination Hormonal Contraceptive for Men

Abstract

The study regimen led to near-complete and reversible suppression of spermatogenesis. The contraceptive efficacy was relatively good compared with other reversible methods available for men. The frequencies of mild to moderate mood disorders were relatively high.

Development of Novel Male Contraceptives

“…46 This led to a WHO/CONRAD larger trial testing intramuscular injections of TU and noresthisterone enanthate ( Figure 3b) every 8 weeks to prevent pregnancy. 47 Although Organization. a For clarity, men/couples who dropped out for reasons other than failure to suppress pregnancies or sperm rebound, are omitted from the efficacy evaluable population.…”

“…The first androgen‐progestin combination efficacy study with 52 couples was published in 2003 . This led to a WHO/CONRAD larger trial testing intramuscular injections of TU and noresthisterone enanthate ( Figure b ) every 8 weeks to prevent pregnancy . Although the regiment was 93% efficacious for pregnancy prevention in treated men, the study was stopped early due to concerns about side effects.…”

“…To date, there have been six large male contraceptive efficacy studies in which the hormonal regimen was used with the intention of preventing unintended pregnancy . Five of these studies enrolled men with oligospermia.…”

“…No contraceptive study conducted to date has found an increase in cardiovascular complications or blood clots, but none of these studies was powered to study this outcome, and these events are uncommon in the young men participating in these studies. The recent WHO/CONRAD trial, which used a long‐acting injectable combination therapy with TU and noresthisterone enanthate, demonstrated a high degree of contraceptive efficacy, but was stopped early due to side effect concerns, particularly related to concerns about negative effects on mood . Clearly, more work to understand the causes and implications of these adverse effects will be necessary before a hormonal regimen will likely be approved for widespread use.…”

Rising to the challenge of male hormonal contraception

“…However, a recent large study assessing intramuscular injections of norethisterone enantate combined with testosterone undecanoate administered every eight weeks was stopped early due to a high rate of severe adverse events including acne, injection pain, erectile dysfunction and mood changes. 8 "There is a lot of current concern about the safety of androgens in men," Professor Page says. "It is important to emphasise that current male hormonal contraceptives are designed to utilise physiological doses of testosterone."…”