A Pill a Day Keeps the Sperm Away
Other contraceptive possibilities, some of which are promising:
- A non-hormonal pill that prevents the release of sperm into the semen. So far, experiments with genetically altered mice have had some success.
- Non-hormonal compounds that prevent the development and maturation of sperm cells. So far, only animal tests have been completed. However, there are reports that the compounds can cause up to a 40% to 50% reduction in testicular size.
- Plant extracts like gossypol and Tripterygium wilfordii. Gossypol was used in daily doses in Chinese men, but Tripterygium has primarily been studied in animals. They inhibit sperm production, but the effects may be irreversible, and gossypol was found to shrink the testicles.
- Nifedipine, a calcium channel blocker used for high blood pressure, appears to cripple sperm -- making them unable to fertilize the egg.
Mifepristone, known as RU-486, the abortion-inducing drug, has been shown to stop sperm from moving normally and fertilizing eggs. But it has hormonal side effects that make it useful as a tool for further research only.
- A silicone plug injected into the vas deferens, to stop the sperm from entering the semen. Supposedly, it's reversible in the hands of a "skilled" surgeon. Hundreds of thousands of Chinese men have undergone the procedure.
Although it seems there are many irons in the fire, there really has been little research into male contraceptives, and very little support from the pharmaceutical companies. Why? "Well, it's not really regarded as a terribly sexy area -- is it really?" Anderson asks. "People have always treated it with a bit of suspicion and thought, 'Well, it's a bit of a dead end.' It's not something that people have thought is particularly wonderful."
If there's no perceived market, there's no money for research. DePaolo also mentions that there has been some hesitation at developing hormonal contraceptives for men, because the pill for women wasn't exactly a "smooth ride ... It's been one that's been quite tenuous with the side effects and everything, and there's clearly the potential to have some of these side effects."
Susan Scrimshaw, PhD, the dean of the University of Chicago School of Public Health, tells WebMD it's also hard to ignore the fact that "for many years, there was little or no focus on men because research was biased towards changing women's reproductive capacity.