Male contraceptive found to be safe in early trials

A new birth control pill for men – called dimethandrolone undecanoate or DMAU – is safe when used every day for a month, with hormone responses consistent with effective contraception, according to new research.

The experimental male oral contraceptive combines activity of an androgen (male hormone) like testosterone, and a progestin, and is taken once daily.

The study’s senior investigator, Stephanie Page, said: ‘DMAU is a major step forward in the development of a once-daily ‘male pill’. 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.’

Progress toward a male birth control pill has stalled because available oral forms of testosterone can cause liver inflammation, and clear the body too quickly for once-daily dosing. However, DMAU contains undecanoate, a long-chain fatty acid, which slows clearance.

The study on 83 healthy men, between the ages of 18 and 50, and took place at the University of Washington Medical Centre. The investigators tested three different doses of DMAU (100, 200, and 400mg) and two different formulations inside the capsules (castor oil and powder). Each dose group included five subjects who were randomly assigned to receive an inactive placebo and another 12 to 15 men who received DMAU. Subjects took the drug or placebo for 28 days once daily with food (DMAU must be taken with food to be effective).

At the highest dose of DMAU tested, 400 mg, subjects showed ‘marked suppression’ of testosterone levels and two hormones required for sperm production. The low levels are consistent with effective male contraception shown in longer-term studies.

Page said: ‘Despite having low levels of circulating testosterone, very few subjects reported symptoms consistent with testosterone deficiency or excess. These promising results are unprecedented in the development of a prototype male pill. Longer term studies are currently under way to confirm that DMAU taken every day blocks sperm production.’

All groups taking DMAU did have weight gain and decreases in HDL (“good”) cholesterol. All subjects passed safety tests, including markers of liver and kidney function.