So What’s The Deal With Male Contraception?
Contributor Vivian Cheng
Everyday your alarm rings at the same time, with a message along the lines of:
“Don’t contribute to the seven plus billion,”
“No new kids,”
or “Anti-baby time.”
For all you ladies that take the pill, I understand your frustration — it’s a hassle to take a pill everyday — that’s why talks of a male birth control pill garner so much attention. However, as with most discourse in popular science, lots of misconceptions surround the topic.
The few male oral contraceptives in the trial stage, such as Testosterone Undecanoate and Testosterone Enanthate, have been withdrawn because of concerning side effects. For example, some candidate male contraceptives decrease muscle mass because of the decreased levels of testosterone.
So how do these drugs work? They work by decreasing intratesticular FSH and testosterone concentrations to suppress sperm production. Administering exogenous testosterone and testosterone derivatives can inhibit testosterone release via negative feedback systems.
Sounds simple right? In practice, it’s much more complex.
Reducing intratesticular testosterone may lead to issues like hypogonadism — a gonad deficiency that can permanently impair fertility — so patients require additional hormone supplements to replace this testosterone. For these patients, the difficulty lies in adequate sperm reduction while maintaining healthy testosterone levels. Exogenous testosterone also leaves the body quickly, so men would have to take the pill many times a day to maintain plasma levels of the drug.
There are also unknowns with regards to male reproductive physiology. For example, there have been studies that challenge the traditional dogma of spermatogenesis, by showing that testosterone may not be essential for sperm production (only in mice models, however).
For women, the pill works by maintaining consistent levels of estrogen and progesterone so that the body believes it’s pregnant. Essentially, the elevated estrogen levels prevent LH and FSH secretion such that ovulation does not occur. Estrogen and progesterone have secondary mechanisms that work to prevent pregnancy. For example, they maintain thick mucus viscosity and prevent uterine contractions to prevent fertilization.
Despite the challenges of designing the male pill, scientists are actively pursuing research in this field because of its potential market value. One promising innovation is a contraceptive gel. This gel aims to steadily add testosterone back into the bloodstream through the skin, at low enough levels to avoid spermatogenesis — a process that requires 50 to 100x the testosterone concentration in blood.
Scientists are even looking at non-hormonal methods, beyond the condom and the vasectomy, but have not tested these products to the same extent as they did in women. One product tested in mice is H2-gamendazole, which prevents sperm from reaching maturity.
These studies show us that even more research should be conducted in this field to provide more diverse contraceptive options. While the male contraceptive pill is great in theory, the complications in place prevent us from obtaining a male pill in the near future.