Are we on the verge of a new male contraceptive?
The demand is there, coming from both men and women, although there is still that concern that men could not be trusted to take a pill every day. Research in the area of male contraceptives is underfunded compared to the more attractive and lucrative areas related to form and function. Enhancing libido and genitalia attract many more dollars than looking for a male contraceptive. Besides, don’t women already have that taken care of?
I first wrote about non-barrier male contraceptives in a Pharmacy Times article in October of 1995, predicting that a male contraceptive pill was coming soon, or, “at least by the next millennium.” The new millennium is here and there may be some new options beyond the condom for men willing to take the responsibility of baby prevention into their own hands, as it were. That reminds me of the poor guy whose only date was with his right hand… he always got Valentine’s Day confused with Palm Sunday.
You can read the original article and other predictions on this page.
The Chinese and the Brazilians have considered gossypol, a cottonseed component, as a male contraceptive. At first things looked pretty successful as the gossypol pill provided a very high degree of contraception, reportedly by blocking enzymes necessary for sperm to mature. Problems arose when frequent hypokalemia and rates of permanent infertility proved unacceptably high. Brazil almost got the gossypol pill, Nofertil (subtle Brazilians!) on the market at about the same time my PT article appeared. The FDA considers it a toxic substance and spends some time and money making sure it does not turn up in animal feed. It’s still being looked at as a kind of chemical vasectomy for its ability to cause permanent infertility.
In India, they have been working on a reversible contraceptive for men that involves a direct injection into the scrotum. Vasalgel (TM), a polymer, is injected into the vas deferens, preventing sperm from traveling beyond the epididymis. A product called RISUG (TM), Reversible Inhibition of Sperm Under Guidance, has been used by Indian men for over 15 years. Although the R stands for reversible, the reversing process has only been tried on animals, not “officially” on humans. The hope is that the newer polymer Vasalgel is more easily reversed and has been licensed for study in the US. Other polymers have been used in China and elsewhere to plug the vas deferens.
The search for a male hormonal birth control pill is ongoing but may have been abandoned. Most hormonal choices that may limit or stop the production of viable sperm are not good candidates for oral use, either being quickly destroyed by stomach acid and digestive enzymes or simply not being absorbed into the bloodstream. That means the needle is most likely guys, although their may be something in a couple non-hormonal drugs that seem to reduce male fertility.
Dibenzyline (phenoxybenzamine), for pheochromocytoma and Mellaril (thioridazine), a behavioral drug both seem to have a peculiar effect on male orgasm. Relax guys, you’ll still have an orgasm, but it will be a cum-free cum. Here’s the rub: Many drugs, notably α-adrenergic antagonists, have effects on contractility of the vas muscles and thus normal ejaculation. It’s a common side effect of these drugs. Normally, sperm and seminal fluid are propelled through the vas by the orchestrated contraction of both longitudinal and circular muscles. It’s quite a trip, starting in your balls and passing up and behind your bladder, right through your prostate, up the shaft of your penis and into the loving environment provided by your partner. Anyway, phenoxybenzamine and thioridazine are particularly good at blocking the contraction of the longitudinal muscles and allowing the circular muscles to contract. The net effect is to close down the highway. We’re trying to take advantage of a side effect here, so much research still needs to be done. Yet studies are ongoing to find more specific agents that will have targeted effect with few side effects. This is also an area being examined to find a drug for premature ejaculation. The calcium channel blocker, nifedipine. is also being looked at because it was observed that men taking it had altered sperm that have a diminished capacity to latch onto the egg.
It’s illuminating to see that there are a huge number of articles (mine included) in the past few decades promising a male contraceptive pill and still nothing has reached the market. Perhaps we are chasing unicorns.