A Pill a Day Keeps the Sperm Away
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.