A small, recently released study shows a newly developed oral contraceptive for men appears to be both effective and safe.
The research, presented at the Endocrine Society's annual meeting in Chicago by researchers from the University of Washington in Seattle, studied 83 men between the ages of 18 and 50. The participants' testosterone levels dropped significantly along with two hormones essential for sperm production.
Like the pill for women, the experimental contraceptive — called dimethandrolone undecanoate, or DMAU — affects hormones and is taken once a day, said the study's senior investigator, Stephanie Page, a professor of medicine at the university.
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"DMAU is a major step forward in the development of a once-daily 'male pill'," Page said Sunday in a statement by the Endocrine Society. However, Page cautioned that the study size was small and that much more research needs to be done.
"We're confident, but this [current] study was too short," she told Medscape Medical News. "Ultimately, we need to do a study with couples. There's lots of work to do."
Progress toward a male birth control pill has been slow, Page said, because of concerns about liver and kidney damage and, until the new formulation, the need for two or more doses a day. However, DMAU contains undecanoate, a long-chain fatty acid, which Page said solves these issues.
At the highest dose of DMAU tested, 400 mg, subjects showed "marked suppression" of levels of their testosterone and two hormones required for sperm production. The low levels, Page said in the Endocrine Society statement, are consistent with effective male contraception.
The treatment, however, is not without side-effects, with reports of weight gain and decreases in HDL ("good") cholesterol. However, Page said both were mild and all subjects passed safety tests, including markers of liver and kidney function.
"These promising results are unprecedented in the development of a prototype male pill," she added.
During a press briefing reported by Medscape Medical News, Page showed data from a multinational survey in which 60% to 80% of men indicated that they would be interested in a reversible male contraceptive other than condoms if one were available.
In addition, she said, "Many men say they would prefer a daily pill as reversible contraceptive, rather than long-acting injections or topical gels, which are also in development," she added.
At the media briefing, Page said her team has just begun a three-month study to expand on its research.