Sean Swint is an Atlanta-based writer who came to WebMD after a writing and producing stint at CNN/Headline News. Before that, he earned his keep as an assistant director and set production assistant in the film and commercial industry. His credits include such films as “Driving Miss Daisy” and “Not Without My Daughter.” Upon graduating from the University of Massachusetts at Amherst with a degree in journalism and English, he was editor of a weekly Atlanta metro-area newspaper.
WebMD Medical News
Reviewed by Dr. Pamela R. Yoder
July 19, 2000 — They multiply by the millions each day, they travel in packs, and once unleashed they are single-minded in their goal: succeed or die. Sperm, it’s fair to say, are a relentless lot.
And they are no easier to stop before they’re released. Which is one of the reasons a male contraceptive has been such an elusive goal. It’s easier to stop a woman’s monthly ovulation than it is to completely stop the production of millions of sperm a day. After all, it only takes one of the little critters to do the trick.
But it seems a team of researchers in Scotland may have hit on the right formula to stop sperm production, and it could hit the market within the decade. Sixty men, half in Scotland and half in China, were given a regimen consisting of a daily pill that contained a steroidal hormone and an implant placed under the skin, such as Norplant is used in women.
The pill contains a synthetic hormone found in some female oral contraceptive pills called desogestrel, and the implant contains testosterone.
Here’s the basic logic: the pill’s steroidal hormone works to block the production of sperm, but a side effect is it minimizes the production of the body’s testosterone. That is what makes men men, so to speak. Without it, they can lose facial and pubic hair, grow breasts, or suffer a whole host of side effects. So the implant replaces the body’s testosterone.
“I think keeping the testosterone concentrations normal, neither too high or too low, is perhaps the secret,” says Richard Anderson, MD, PhD, clinical scientist at the University of Edinburgh Centre for Reproductive Biology. Anderson and his colleagues developed the regimen.
He says the men’s sperm counts dropped to zero — “not a single sperm to be seen.” Plus, “It starts working immediately, but it does take a while for the sperm count to fall to zero. It’s like after a vasectomy; it takes several months, often, to go down to zero, because you have to wash out all the sperm that are already produced. But some men have sperm counts, within six to eight weeks, of zero.”
Louis DePaolo, PhD, program director for the National Institute of Child Health and Development’s reproductive sciences branch, explains it further by saying the steroidal hormone stops the pituitary gland in the brain from releasing hormones that set sperm production into motion. The testosterone is mainly at “maintenance levels, to maintain libido and all the other actions that androgen [male hormone] has in the body.”
Anderson says the treatment is 100% reversible, with few side effects. “Most people feel absolutely normal; they don’t notice any difference at all. Some of the men put on a couple of pounds, but not enough to drop out of the study, and we didn’t have any other significant side effects.”
A European pharmaceutical company called Organon plans to market the product when it’s ready, which will be a minimum of five years, says Anderson. Organon provides the products for the trials, but otherwise, he says, the studies are funded by research grants.
This type of hormonal research, which follows in the footsteps of previous research leading to the female pill, has been going on for years, says DePaolo, and is the most heavily researched form of male contraceptive. But it’s not all.
There’s been a lot of effort invested into injected vaccines that are antibodies to specific proteins involved in fertilization. These antibodies, whether in the sperm or on the egg’s surface, attempt to prevent the sperm from binding to it, says DePaolo, adding that there have been some promising leads that seem both effective and reversible, “but it’s not something that’s easily controlled.”
Outside of condoms or vasectomies, there have also been many other contraceptive possibilities tested, some to no avail; some are still being researched. Testosterone alone was shown to reduce sperm production in most men, but depending upon the type and amount, there could be serious side effects, ranging from the lowering of “good” cholesterol, an increase in weight and decrease in the size of the testicles, to acne, mood changes, or less than complete effectiveness.
The estrogen derivatives, such as the hormonal steroid used in the Scottish trial, were added to try to get around some of these side effects. They may have gone under different names, with slightly different effects, but the goal was the same. They’ve all been used in conjunction with testosterone that’s been injected or given in a patch or implant.
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.
“An interesting question is the strength of motivation for men to use it, since men don’t get pregnant,” she says.
DePaolo says pharmaceutical companies in the U.S. still have not “bought into” the idea that men “are ready to be responsible for their fertility,” whereas a couple of pharmaceutical companies in Europe appear to believe, and invest in the belief, that European men are more willing to use contraception.
In fact, a recent survey of men in Edinburgh, South Africa, Hong Kong, and Shanghai by Anderson and his colleagues found about 90% thought a male hormonal contraceptive was a good idea, and about 66% said if it was available now, they would be willing to use it in the near decade.
But would women believe the men really used it? DePaolo calls that issue the “trust factor,” because with men, “how are you going to tell” if in fact the man has taken the contraceptive?
“If men do use it, it will have a freeing effect for many women who have biological or other reasons for not using some of the more common female contraceptives. On the other hand, many men may not want to father children outside of a conscious decision to do so. It may be most important for committed couples, where the man is willing to take this responsibility,” Scrimshaw tells WebMD.
Contraception, whether male or female, does not alone constitute safe sex, which Scrimshaw concedes would probably be hurt “to some extent” by a male contraceptive.
DePaolo says, “one of the big areas in contraception in general is the development of spermicide-microbicide combinations to combat the spread of sexually transmitted diseases. The steroid contraceptive pills aren’t going to do that unless you wear a condom.”
Many of these questions will inevitably be answered when some form of male contraception does reach the market. Will it cause a groundswell similar to the female pill? Probably not, with many researchers calling the male pill an evolution, not a revolution.
Scrimshaw agrees. “It will have an impact, but I doubt that it will have the same impact as the female pill,” she says. “For one thing, many of the cultural, social, [and] sexual changes facilitated by the control over reproduction represented by the pill have already taken place. Also, in many cultures, it will not be easy for men to accept this method.”
Still, science has come a long way. DePaolo says there’s a “semi-movement” towards male contraception, and the field of science is progressing rapidly, but “to say there are things on the horizon, it’s too early to tell.”
Male ‘Pill’ May Be Available This Decade
By Sean Swint