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Promising Male Birth Control Pill Is Safe and Effective, Study Says

2 minute read

The female birth control pill has stood on the market alone for decades. Now, a male birth control pill could be inching closer to reality, according to the results of a small new study presented in Chicago at the annual Endocrine Society meeting. It found that an experimental drug is both safe and effective.

Researchers who conducted a month-long trial involving 83 men said the once-daily pill lowered hormone levels similarly to other forms of longer-term contraceptives—without signs of testosterone deficiency or excess. The pill, called dimethandrolone undecanoate, or DMAU, is structured similarly to the female pill, according to study author Dr. Stephanie Page. The drug is being developed by the National Institutes of Health (NIH); the group also funded the study, which has not yet been published in a peer-reviewed journal.

“DMAU is a major step forward in the development of a once-daily ‘male pill’,” said Page, who is a professor of medicine at the University of Washington, in a statement. “Many men say they would prefer a daily pill as a reversible contraceptive, rather than long-acting injections or topical gels, which are also in development.”

A daily pill for males has long been elusive to pharmaceutical developers, as oral testosterone in previous forms may damage the liver or clear the body too quickly to work in just one pill per day. The pill form that DMAU takes, Page said, contains a long-chain fatty acid to make the contraceptive linger longer in the body. Other forms of contraceptive for men are also in development.

The men who participated in the double-blind study took a placebo or one of three different doses of DMAU for 28 days. The study authors said there was “marked suppression” of testosterone and of two hormones necessary for a man to produce sperm for those who took 400mg of DMAU, the highest dose.

Notably, the researchers said few people had symptoms of excessive or deficient testosterone levels, and all subjects passed safety tests that ensured proper liver and kidney function.

More research is needed before DMAU becomes a viable option for male birth control. “Longer term studies are currently under way to confirm that DMAU taken every day blocks sperm production,” Page added in the statement.

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Write to Julia Zorthian at julia.zorthian@time.com