Male birth control pill lowers testosterone without side-effects, clinical trial shows

ATLANTA — Birth control for men may be one step closer to reality after a clinical trial reveals two experimental pills can successfully lower testosterone levels without side-effects.

Researchers say the two candidates, DMAU and 11β-MNTDC, come from a group of drugs called progestogenic androgens. This class of medication suppresses testosterone, which in turn lowers a man’s sperm count.

However, lowering a man’s testosterone levels typically leads to undesired side-effects, including weight gain, less muscle mass, weaker bones, and fatigue. During the new drug trial, study authors found that most of the men were willing to continue taking the contraceptive pills, suggesting that the new drugs’ side-effects were more tolerable.

“Male contraception options are currently restricted to vasectomy and condoms, and are thus extremely limited as compared to female options,” says lead researcher Tamar Jacobsohn of the Contraceptive Development Program at the Eunice Kennedy Shriver National Institute of Child Health and Human Development, in a media release.

“Development of an effective, reversible male contraceptive method will improve reproductive options for men and women, have a major impact on public health by decreasing unintended pregnancy, and allow men to have an increasingly active role in family planning.”

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Researchers recruited 96 healthy men to take part in two Phase 1 clinical trials during this study. In each one, the men randomly received two or four-pill doses of a male birth control pill or a placebo for 28 days.

For men receiving DMAU and 11β-MNTDC, testosterone levels dropped after just seven days. Meanwhile, testosterone levels stayed the same in the control group.

Results reveal 75 percent of the men taking the contraceptive said they wanted to keep taking it in the future. Moreover, those on the four-pill (400 milligram) daily dose saw their testosterone levels drop lower than those on the two-pill, 200-milligram daily regimen. However, study authors note that there was little difference between those two groups in terms of their willingness to continue taking male birth control pills.

“Men’s positive experiences in clinical trials and high ratings of acceptability for this male pill should serve to excite the public about male birth control being potentially widely available in the coming decades,” Jacobsohn concludes.

The team presented their research at ENDO 2022, the Endocrine Society’s annual meeting.