A new birth-control pill for men might soon be a reality. It's called dimethandrolone undecanoate (DMAU).
"DMAU is a major step forward in the development of a once-daily 'male pill'," Professor Stephanie Page, senior investigator on the study told Science Daily. "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," Page added.
Researchers at the University of Washington Medical Centre tested three doses of DMAU on 100 healthy men between 18 and 50 years old, 83 of whom completed the study.
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.
"These promising results are unprecedented in the development of a prototype male pill," Paige told The Telegraph.
Here are five things you need to know about the newly tested pill:
1. You can take one a day
So far, efforts to create a pill like a female contraceptive, administered in one daily dose, have been frustrated by the fact that men metabolise quickly, clearing out any hormones such pills bring and so requiring instead two doses a day.
DMAU, however, includes a long-chain fatty acid that slows down the clearance, allowing just one dose to be taken each day.
2. It is safe to use
Male hormonal pills in the past have caused liver inflammation. All subjects in this trial passed their safety tests, including markers of liver and kidney function.
Hormone responses were also found to be consistent with effective contraception.
3. The pill works only if taken with food
Volunteers took the drug for 28 days once daily with food. DMAU must be taken with food to be effective, emphasised Page.
Notably, however, all groups taking DMAU experienced some weight gain, as well as decreases in HDL ("good") cholesterol.
4. It does not harm one's sex drive
Low testosterone levels can lead to loss of sex drive and fatigue, but most of those on the trial did not appear to suffer. "Despite having low levels of circulating testosterone, very few subjects reported symptoms consistent with testosterone deficiency or excess," Page said.
5. This is not the end, yet
As this was a trial experiment, "longer-term studies are currently underway to confirm that DMAU taken every day blocks sperm production," Oage said – adding, however, "these promising results are unprecedented in the development of a prototype male pill."