Male contraceptive pill is safe and effective in tests in mice

Alex Wilkins

The contraceptive pill is 99 per cent effective in preventing pregnancies in mice. Some researchers warn that safety concerns could prevent the drug from reaching the market, even though human trials are being planned.

There have been many attempts to make an effective and safe male contraceptive. Md al Noman at the University of Minnesota says that non-hormonal contraceptives have fewer side effects than hormones.

Birth control pills are less tolerant of side effects if people are not taking it for a disease.

He and his colleagues gave male mice a daily dose of a molecule called YCT529 and found that their sperm count plummeted. The mice were able to reproduce again after four and six weeks after they stopped receiving the treatment.

The compound didn't show any toxicity when we went to even 100 times higher dose.

The team tested more than 100 compounds to find a drug that targets retinoic acid receptor alpha. The effects of retinoic acid are important in cell development and sperm formation.

Read more: No contraceptive is perfect, but can you trust apps to stop pregnancy?

There were no side effects apart from the inability to produce sperm when the mice were genetically edited.

Noman and his colleagues have licensed their drug to a private company that is planning to conduct human trials in the US later this year.

Noman and his team didn't observe any side effects in mice, but this doesn't guarantee that the drug will be safe in humans, says Richard Anderson at the University of Edinburgh, UK.

The University of Edinburgh's Richard Sharpe says that a compound with such activity would likely have side effects.

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