Male birth control study halted due to ‘mood swings’ in participants

Researchers in Switzerland hit on a male birth control shot that showed a nearly 96 per cent success rate, but the study was cut short due to complaints of unpleasant side effects including mood swings, depression and acne.

Published on Oct. 27 in the Journal of Clinical Endocrinology & Metabolism, the study enlisted 320 men between the ages of 18 and 45 who were in monogamous relationships with women for at least one year. Each participant received an injection of hormones (progestrogen and androgen) to suppress sperm count every eight weeks for 56 weeks, and provided semen samples at each interval. The hormones were found to be effective in lowering sperm counts within 24 weeks in 274 participants, totalling a nearly 96 per cent success rate. Four pregnancies occurred during the course of the study.

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“The study found it is possible to have a hormonal contraceptive for men that reduces the risk of unplanned pregnancies in the partners of men who use it,” study co-author Mario Philip Reyes Festin, MD, of the World Health Organization in Geneva said to ScienceDaily. “Our findings confirmed the efficacy of this contraceptive method previously seen in small studies.”

However, researchers halted the study when 20 men dropped out complaining of adverse side effects including depression, mood disorders, pain at injection site, muscle pain, increased libido and acne. Despite these issues, more than 75 per cent of participants said they would be willing to use this form of birth control.

“More research is needed to advance this concept to the point that it can be made widely available to men as a method of contraception,” Festin said. “Although the injections were effective in reducing the rate of pregnancy, the combination of hormones needs to be studied more to consider a good balance between efficacy and safety.”

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In an interview with Broadly, another co-author of the study, Richard Anderson, minimized the concern surrounding the participants who withdrew from the study saying, “a lot of people reported the side effects in quite a mild way.”

“At the end of the day, it’s going to be a matter of someone taking it, and if they find the side effects too bad, they’re going to stop taking it and look for something else,” he said. “It’s a matter of trying to improve the option choices so that people find something that works for them.”