Male Contraceptive Pill Passes Safety Test in Humans
An experimental birth control pill for men has successfully passed tests of safety when participants used it daily for a month, according to scientists who said that the drug does not affect libido.
The contraceptive called 11-beta-methyl-19-nortestosterone dodecylcarbonate (11-beta-MNTDC) is a modified testosterone that has the combined actions of a male hormone (androgen) and a progesterone.
"Our results suggest that this pill, which combines two hormonal activities in one, will decrease sperm production while preserving libido," said Christina Wang, from Los Angeles Biomed Research Institute (LA Biomed).
The study took place in 40 healthy men at LA BioMed and the University of Washington in the US.
Ten study participants randomly received a placebo capsule, or dummy drug. The other 30 men received 11-beta-MNTDC at one of two doses; 14 men received 200 milligrams, or mg, and 16 got the 400 mg dose.
Subjects took the drug or placebo once daily with food for 28 days.
Wang said drug side effects were few, mild and included fatigue, acne or headache in four to six men each.
Five men reported mildly decreased sex drive, and two men described mild erectile dysfunction, but sexual activity was not decreased, she said.
Furthermore, no participant stopped taking the drug because of side effects, and all passed safety tests.
Effects due to low testosterone were minimal, according to Stephanie Page, a professor at the University of Washington, because "11-beta-MNTDC mimics testosterone through the rest of the body but is not concentrated enough in the testes to support sperm production." Levels of two hormones required for sperm production dropped greatly compared to placebo, the researchers found. The drug effects were reversible after stopping treatment, Wang said.
Since the drug would take at least three 60 to 90 days to affect sperm production, 28 days of treatment is too short an interval to observe optimal sperm suppression, she said.
They plan longer studies, and if the drug is effective, it will move to larger studies and then testing in sexually active couples.
"Safe, reversible hormonal male contraception should be available in about 10 years," Wang predicted.
The experimental contraceptive, 11-Beta-MNTDC, is a "sister compound" to dimethandrolone undecanoate, or DMAU, the first potential male birth control pill to undergo testing by the same research team.