New birth control pills for men show 99% effectiveness

Researchers at the University of Minnesota in the US reported about the creation of a new non-hormonal male contraceptive pill that destroys a certain protein involved in the formation of spermatozoa.

Tests of the drug on mice showed effective prevention of pregnancy, reversibility of action within a few weeks and no side effects.

The pill targets the RAR-α (RAR-alpha) protein, which is involved in cell differentiation and sperm production. Previous research has shown that suppressing the RAR-α gene in mice renders them infertile.

Now scientists have investigated about 100 different compounds for the ability to inhibit RAR-α in cells. YCT529 did the best job, targeting RAR-α about 500 times more than two other related RAR proteins. This suggests that its use should significantly reduce the risk of side effects.

YCT529 was tested in male mice with oral doses for four weeks. The number of spermatozoa in animals decreased significantly, and the effectiveness of the drug in preventing pregnancy was 99%.

The scientists did not observe any side effects, and, importantly, the treatment was reversible: the mice successfully bred four to six weeks after stopping the drug.

These results allow researchers to plan human clinical trials, which should begin in late 2022.