What’s the Hold-up on Male Contraception?

There are many female contraceptives to choose from, yet only two male options: condoms and vasectomy. Expanding male contraception methods could help reduce unintended pregnancies, which still account for almost half of all pregnancies in the U.S. and globally. So why are we still waiting for a male pill?¹

With half of states expected to implement full or partial abortion bans following the Supreme Court’s draconian decision to overturn Roe v. Wade, access to safe and effective contraception is more important than ever before.

Encouragingly, the Roe reversal prompted men around the country to step up and do their part to prevent unintended pregnancy by seeking out a vasectomy. Vasectomy, which involves cutting and sealing the vas deferens (the tubes that carry sperm), is highly effective but not always reversible, so is best suited to men who are certain they don’t want more or any biological children.

For men who have not yet completed their families, there is currently only one other pregnancy prevention option: condoms. When used correctly, condoms have a high efficacy rate, and they are unique among contraceptives in their ability to prevent sexually transmitted infections in addition to pregnancy. The global health benefits of condom use are tremendous, but many couples in committed relationships prefer longer-acting “set-it-and-forget-it” methods.

Birth control has largely been considered a women’s issue since the first contraceptive pill was approved for use in the 1960s. In the ensuing decades, many other methods were developed, from diaphragms, rings, and IUDs (intrauterine devices) to implants, patches, and injectables — all of them designed for the female reproductive system.

Why so few male options?

The longstanding joke about new male methods is that they’ve been five years away from market availability for the past 50-60 years. There are a couple reasons for this delay: The first is biological — women typically only ovulate once a month, whereas men produce millions of sperm every day. Researchers argue that it is easier to block one egg than to incapacitate a whole army of swimmers.²

The main reason research into male contraception has been slow, though, is lack of funding. The pharmaceutical industry has been reluctant to invest in the development of new male options because there is a perceived lack of demand for them. (In recent years this has proven to be untrue, however — see ‘Changing attitudes’ below.)

A promising trial on a hormonal injection designed to lower sperm count caused a big outcry in 2016 when it was announced that it was canned due to a high incidence of undesirable effects, especially acne, as well as altered libido and mood swings. In response, women around the world were quick to point out that these are common side effects of hormonal contraception which they have been enduring for decades, alongside weight gain, and increased risk of cancer and dangerous blood clots. But contrary to what many media outlets claimed, the trials weren’t halted because the participants couldn’t handle the side effects. It was an independent review board that made the decision based on the high number of adverse events being reported.

Men’s tolerance for unpleasant side effects is expected to be naturally lower because they aren’t the ones who get pregnant — the consequences of unintended pregnancy are almost always worse for women. Pregnancy and childbirth complications kill more than 800 women and girls every day, and babies and young children’s demands on their mothers are generally more intense, both physically and mentally, than those on their fathers. An unwanted pregnancy has the potential to claim or derail a woman’s life, especially if she cannot access safe, legal abortion services.

But unintended pregnancies negatively impact men too, and surveys show that many men are a lot more open to sharing the burden of contraception than what is generally believed. In the aforementioned study, three-quarters of the participants who didn’t drop out said that they would have been willing to continue with the contraceptive jab.

Changing attitudes

A 2017 US-based survey by the Male Contraceptive Initiative (MCI) found that out of 17 million men who wish to prevent pregnancy, almost half said they were “very likely” to try new male methods, and a third said they were “somewhat likely” to do so. This means that around 80% of men surveyed are potentially interested in using male contraception.

Men who have seen their female partners struggle with side effects are often keen to help share the burden, and single men have also expressed interest in having the power to control their own fertility. There is clearly a strong demand for male birth control now, which has helped boost recent research. It will likely still take several years before any new method becomes available, but there are several promising new developments.

Hormonal methods

Topical gels

Topical, or transdermal, gels are applied to the skin. Clinical trials are currently underway for NES/T, a gel combining Nestorone, a progestin (or synthetic progesterone), with testosterone. It’s applied to the shoulders daily and is absorbed through the skin, lowering sperm production. A 2019 study showed the gel lowered sperm count enough to prevent pregnancy in 84% of users.

Pills

Another hormonal method currently in clinical trials is dimethandrolone undecanoate, or DMAU, a pill that’s taken daily with food. It also combines an androgen — a male hormone — with progestin and is designed to lower sperm production.

While DMAU trials are still in early stages, researchers have found that it effectively suppresses the hormones required for sperm production and is generally well tolerated. Reported side effects are similar as for female hormonal contraception, including acne, headaches, and weight gain. DMAU is also under development in injectable form.

Non-hormonal methods

Implants

Reversible Inhibition of Sperm Under Guidance (RISUG) is a promising method that has been under development in India for several decades and is currently awaiting regulatory approval. A similar American product called Vasalgel is currently in pre-clinical trials.

RISUG and Vasalgel are polymer gels that are injected into the vas deferens and work like a reversible vasectomy, effectively blocking sperm from getting into semen (without affecting ejaculation or sensation). RISUG reportedly lasts for up to 10 years and can be reversed by flushing out the polymer with an injected solution. Trials involving more than 300 men showed that the product was 97% successful at preventing pregnancy. In addition, other than mild pain and swelling following the injection, no adverse side effects were reported.

ADAM is a hydrogel that is also injected into the vas deferens to block sperm. The company developing it says it’s designed to last a year, after which the gel liquefies on its own, restoring normal sperm flow. The product has been approved for a first round of human clinical trials in Australia.

Pills

EP055 is a new pill that works by binding to Eppin, a protein on the surface of sperm, impairing their mobility. It’s a short-term contraceptive that can be taken daily or on-demand. Not much is known about its efficacy at this stage as human trials are yet to begin.

Another pill, YCT529, is about to enter its first human trial. Experiments on mice showed it to be 99% effective in preventing pregnancy, fully reversible, and with no noticeable side effects. YCT529 works by inhibiting one of the receptors that bind vitamin A, thereby halting sperm development.

A new era of family planning

With all the progress being made on new male methods, it hopefully shouldn’t be too much longer before some of them become publicly available. In the meantime, interested men can look into participating in the many clinical trials currently underway. To learn more about how to help, visit MCI’s website.

¹ This blog post uses gendered language to discuss the reproductive systems of men and women and how they differ vis à vis contraceptive options. We recognize that some men have ovaries and some women produce sperm.
² A counterargument is that for men with multiple sexual partners, it makes more sense to focus on their ability to prevent pregnancy because women can only carry one pregnancy per year, whereas there is no known limit to how many children a man can father within that same period. Just look up Genghis Khan, one of the most prolific procreators in known history (you may even have some of his genes). If the Mongol emperor had been on birth control, it would have significantly changed demographic history.