Although this has been tried before, the current attempt seems to be the most prospective one yet.
In fertile men, new sperm cells are constantly made in the testicles, triggered by hormones. Birth control for men is by temporarily blocking this effect without lowering hormone levels to such an extent that it creates side-effects. But this latest pill being, should hopefully achieve this goal without side effects.
Opinion polls suggest many men would consider taking it if a pill did become available. Although opinion polls also suggest that women wouldn’t trust their men to take the pill regularly.
The tests are being conducted by researchers from LA BioMed and the University of Washington’s Prof Christina Wang and colleagues. The Initial “phase one” safety tests with 40 men seemed promising. For the 28 days of the study 10 men took a placebo, while 30 men took the experimental male pill, 11-beta-MNTDC.
And among those taking the androgen-based drug, levels of hormones required for sperm production dropped greatly compared with placebo, returning to normal after the trial.
Side-effects, meanwhile, were few and mild.
Five men on the pill reported mildly decreased sex drive – and two described mild erectile dysfunction – but sexual activity was not decreased, no participant stopped taking it because of side-effects and all passed safety tests.
The researchers behind the work are excited but cautious about the findings.
“Our results suggest that this pill, which combines two hormonal activities in one, will decrease sperm production while preserving libido,”
But bigger, longer trials were needed to check it would work well enough as a birth control.
The pharmaceutical industry had been slow to get behind the idea of a new male contraceptive despite good evidence that both men and their female partners would welcome the additional choice.