Male Birth Control Effective, But Has Negative Side Effects, Study Finds

Male birth control injections are highly effective, but may come with some significant negative side effects, according to a new study published in the Journal of Clinical Endocrinology & Metabolism.

The study looked at a group of 320 test subjects comprised of “Healthy men, aged 18–45 years, and their 18- to 38-year-old female partners, both without known fertility problems.”

The male subjects were injected with a combination of norethisterone enanthate and testosterone undecanoate every eight weeks, according to the report. The combination of the drugs drastically reduces live sperm counts in men.

The study sought to test both the effectiveness of the drugs in suppressing sperm levels in healthy men, and the reversibility of that suppression once treatment ended.

The results were promising in terms of both suppression and recovery.

“Of the 320 participants, 95.9 of 100 continuing users suppressed to a sperm concentration less than or equal to 1 million/mL within 24 weeks,” the study found. “During the efficacy phase of up to 56 weeks, 4 pregnancies occurred among the partners of the 266 male participants, with the rate of 1.57 per 100 continuing users. The cumulative reversibility of suppression of spermatogenesis after 52 weeks of recovery was 94.8 per 100 continuing users.”

That 1.57 percent of pregnancies compares to 5 to 9 percent rate of unexpected pregnancies among users of oral birth control pills, according to the U.S. Department of Health & Human Services. This may suggest that male birth control injections could potentially be more effective than oral contraceptives commonly taken by women. However, it should be noted that the number of subjects in the male birth control study was relatively small. More extensive research would be required to provide greater accuracy.

While the success rate in terms of suppressing sperm levels is promising, there was a downside to the research. Several of the participants who took the male birth control suffered negative side effects. Some of the side effects were significant enough for the men to abandon the study.

“Twenty men discontinued the study due to product-related side effects,” the report reads.

“Of these 20, 6 men discontinued only for changes in mood, and 6 men discontinued for the following single reasons: acne, pain or panic at first injection, palpitations, hypertension, and erectile dysfunction. Eight men discontinued for more than 1 side effect, including multiple reasons related to changes in mood.”

Despite the fact that the male birth control drugs reduce sperm count, an increased libido was another reoccurring side effect listed in the report.

The report concludes that the “contraceptive efficacy was relatively good compared with other reversible methods available for men,” but acknowledges that the “frequencies of mild to moderate mood disorders were relatively high.”

The side effects were troubling enough for the researchers to prematurely terminate the recruitment and injections “following the recommendation of an external safety review committee.”

Despite the promising results of the effectiveness of the drugs, the side effects, and other factors may prevent male birth control may not become widely available any time soon.

CBS SF Bay Area reports that pharmaceutical companies do not appear to be particularly interested in male birth control.

“Their concern may be there’s a lack of profitability, maybe there is a question of gender bias,” CBS medical contributor Dr. Tara Narula says. “There’s a concern of regulatory hurdles. In addition, it’s not as easy to stop 1,500 sperm that are produced per second as opposed to one egg per month.”

The report has been attracting considerable attention on social media and has been trending on Facebook. Some readers and journalists have not taken the supposed side effects of male birth control as seriously as others, and allude to the type of gender bias Narula referred to.

The women’s interest website Broadly posted an article to Facebook with the comment “Dudes, suck it up—just like women have for decades,” referring to the common “side effects and responsibility of hormonal contraception” that women endure when taking birth control pills.

There is still no definitive date for when hormonal male birth control may become available. An article published by Tech Times early this year suggested that the likely date is some time in 2018.

[Featured Image by Spencer Platt/Getty Images]