DUDLEY SETH DANOFF, M.D., F.A.C.S.
I recently appeared on “The Doctors Show” (CBS – TV) to answer questions about the development of a male contraceptive pill.
A lot of interest has been generated because researchers have become more interested, over the past several years, in developing a male contraceptive similar to the female pill. Although this research has been going on for decades, the momentum seems to be increasing and now scientists have potentially found a way to do it. The big question – Will guys take the pill and will ladies trust them?
Current efforts are focused on developing a pill that would block the function of vitamin A in the testes. Theoretically, this would be a way to reversibly turn off sperm production. After 50 years of work, researchers have learned that the conversion of vitamin A to retinoic acid in the testes can be blocked. The main concern is doing this without affecting the function of vitamin A and retinoic acid in other tissues. Mice were tested and it succeeded 100% of the time.
In addition, researchers have also found a hormonal free way to make the testicles forget how to make sperm. They are testing a drug that targets a particular protein, which is critical for sperm production, and it is reversible. When mice were taken off the treatment, they became fertile again.
In addition, there are two classes of drugs on the market, which cause men to have “retrograde” (backward) ejaculation, which, in essence, keeps men from emitting semen at the time of orgasm. However, it is impractical to use them in clinical practice, because one is an anti-hypertensive, and the other an anti-psychotic medication. Without modification, they would adversely affect blood pressure and mood.
It is also known that hormones, delivered by either implants, injections, gels or pills have a profound effect on sperm production. Testosterone is known to suppress the production of sperm by working directly on the testicles and progestin signals the brain to make the testes stop producing testosterone, arresting sperm production. The long-term effects of the use of either one of these two medicines is unknown but, with current knowledge available, could be extremely risky because of increased incidents of heart disease and prostate cancer.
A researcher in India has reported that he is developing a method called RISUG: “Reversible Inhibition of Sperm Under Guidance,” in which a polymer is injected into the vas deferens blocking a sperm transport and is, at least according to the Indian doctor, reversible. It does require a small surgical incision in the scrotum to access the vas deferens. In my judgment, it does not seem any better than a vasectomy, but the jury is still out. The procedure is now in late phase 3 clinical trials in India.
Remember, no contraceptive measure is 100% effective, not even hysterectomy: (abdominal pregnancies can occur even after a total abdominal hysterectomy). RISUG may be a promising
means of birth control for males, but it is too early to draw any conclusions. The current media hype is unwarranted. Science will have to run its course and complete well-designed clinical trials before this, or any method, can be recommended.
There is no question that the true “need” for a male contraceptive pill is compelling. Men make 1,000 sperm a second. At the end of the day, the only effective methods of male contraceptives are vasectomies (successfully reversible in greater than 95% of cases), condoms, or “keep your zipper up!”