Male Birth Control Pill 99% Effective in Mice Studies

There are many available choices for women for birth control, including pills, patches, intrauterine devices, which results in them bearing most of the burning of preventing a pregnancy. Currently, there are no available pills or options, other than condoms and vasectomy for men to help in preventing a pregnancy. Vasectomies can at times be reversed, but is an expensive procedure and is not always successful.

In a recent report, scientists revealed their findings of a non-hormonal male contraceptive that effectively prevents pregnancy in mice, without obvious side effects. 

The team of researchers used a mice model for their study and targeted a protein called the retinoic acid receptor alpha (RAR-α), which is one of the proteins of a family of 3 nuclear receptors that bind to retinoic acid (vitamin A) that plays a role in cell growth, differentiation, which includes the sperm formation; and embryonic development. 

Previous studies had used a compound able to inhibit all 3 members of the RAR family resulting in reversible sterility in male mice, but the team wanted a more specific approach with less potential side effects. 

The researchers identified a compound, that they named YCT529, that inhibited RAR-α almost 500 times more potently than it did RAR-β and -γ. They gave the compound to male mice during 4 weeks, and found that it dramatically reduced sperm counts and was 99% effective in preventing pregnancy. Mice were able to father pups again 4-6 weeks after stopping the compound.

The group will begin testing the compound in human clinical trials by the end of 2022. 


American Chemical Society. (2022, Mar 23). A non-hormonal pill could soon expand men’s birth control options. American Chemical Society, New Releases, 2022. Retrieved from:

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