Plan C It’s been a long time coming, but in the development of the ‘male pill’, science is closer than ever.
W
hy is the male contraceptive so difficult to crack?
In the 1960s, the female contraceptive pill allowed women to take control of their reproductive rights, spurring on the gender revolution. Today, women have at their disposal 15 different types of contraception. In contrast, only three methods of contraception are available to men: use of condoms, vasectomy, and withdrawal. In an already overpopulated world, the need for more effective and diverse options for birth control becomes more pressing by the day. Today, exciting new research brings hope for the discovery of the elusive male contraceptive. Granted, the execution of the male contraceptive has taken a long time, but it is not for lack of trying. An effective contraceptive must be easy to use, reversible and provide sufficient protection without harmful side-effects. In men, this has proven difficult to achieve. The principle behind contraception is simple: stop the male sperm from reaching the female ovum after ejaculation. One approach is to prevent sperm from being produced via hormonal contraception. In the female version of hormonal contraception, women ingest a pill containing a cocktail of hormones which tricks the body into thinking it has already produced its ovum for the month. The male equivalent of this hormone cocktail is testosterone. However, when testosterone injections were tested on men, the results were inconsistent and in some cases, led to irreversible sterility. This closed the door on male hormonal contraception for some time. No alternatives led to promising results until recently when, as is often the case in drug
discovery, reduced sperm production was noticed as a side effect of a drug unrelated to contraception. A derivative of this drug, Gamendazole, was found to reduce spermatogenesis, the process by which sperm are produced. Unfortunately, countless versions of this drug were found to be useless as they either caused side effects including nausea, vomiting, and testicular pain, or could only be delivered to the testicles via injection. Renewed hope for a male pill came this year, when a team led by chemist Dr Gunda Georg from the University of Minnesota took on the challenge of redesigning the molecule to eliminate side effects. By subtly varying the chemical composition of Gamendazole with hundreds of tweaks, the team created a molecule that is more soluble, meaning it can be ingested orally, and more stable, meaning that one dose can last longer in the body. By continuing this process, the researchers are hoping to make the drug more efficient while limiting its side effects. These molecules have not been tested in humans and a commercially available form of the pill is at
least a decade away. However, Dr Georg notes that “[the compound] is the best we have, and after making many compounds, we are on the right track now.” Another promising approach to male contraception is to mechanically block the sperm in the testicles. This is effectively what happens during a vasectomy, a surgical procedure which snips the vas deferens, the tube which brings the sperm to the penis. The ultimate goal is to invent a reversible procedure which would block sperm in the vas deferens. VasalgelTM, a polymer discovered earlier this year, might make this possible. This gel can be injected directly into the vas deferens, blocking the sperm while letting water-soluble molecules through. A study conducted on rabbits showed that the molecule blocks sperm release within 29 days after injection and lasts for at least 12 months, possibly longer. The real improvement of this technique is that the polymer can be flushed out at any time with another injection, making the contraception completely reversible. While tests have only been carried out in animals, a clinical trial in men is scheduled to launch by the end of the year and is estimated to reach the US market in 2018. While it has been a long and tedious process, 2016 has been a pivotal year in the development of the much-needed ‘male pill’, which is now finally within reach. Considering the impact that birth control has previously had on our society, we should expect repercussions beyond contraception. We might be entering a period wherein our societies will once again challenge accepted gender expectations and reproductive rights. Only time will tell.
Marianne Guenot is studying for an MSc in Science Communication Image: CREATIVE COMMONS
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