April 12, 2024

Men are at the front of the line for the best new birth control

A new generation of contraceptives could appear on the U.S. market within the next few decades. One of these, a pill that blocks certain cells from accessing vitamin A, could limit fertility without flooding the body with hormones; another is an injection that temporarily blocks the reproductive ducts. The method most advanced in research is a topical gel that promises to cause temporary infertility when spread daily on the shoulders and upper arms, without affecting mood or libido. “Overall, we haven’t had any serious side effects at all,” Christina Wang, a contraceptive researcher at the Lundquist Institute in California, and one of the gel’s developers, told me.

This upcoming series of treatments will be notable not only for their imaginative delivery methods, but also for their target group: men. For decades, men wanting to control their fertility have been limited to just two imperfect options: condoms or vasectomies. But in recent years, researchers have made tremendous strides toward developing simple, convenient and effective contraceptives for men, with virtually no side effects. Soon, women may no longer be forced to bear almost the entire burden of preventing pregnancy.

But the coming innovations won’t just be about expanding the menu of options for men. Better contraception for men would not be on the horizon without the many scientific paths that contraception for women has paved. Now it appears that female contraception – much of which still carries many unpleasant, sometimes risky side effects – is due to receive some pushback. It’s true that the logistics of keeping an egg from leaving the ovary don’t completely overlap with the mechanisms for keeping sperm out of the female reproductive tract. But in principle, “there are a lot of similarities,” Diana Blithe, head of the NIH’s Contraceptive Development Program, told me, meaning one can easily inform the other. Given what is now being achieved in male contraception, researchers may soon be able to develop new forms of female contraception that are not only more tolerable, but also more on-demand, less invasive, or even useful for men and women . female reproductive systems alike.

In the more than six decades since the birth control pill’s debut, the list of birth control options for women has grown impressively longer. People can opt for barrier methods, or choose between pills, patches and implants; they can get injections a few times a year, or choose an IUD that lasts up to 10 years. “We have so many options, it’s almost like you’re in a breadbasket,” Amy Alspaugh, a nurse and reproductive health researcher at the University of Tennessee in Knoxville, told me.

Read: The human fertility calendar is changing

Many methods are also improving: IUDs, implants and injections now have a longer life and are easier to insert and remove; The doses of hormonal contraception have dropped dramatically. “We actually used to give horses a dose of estrogen and progestin,” Alspaugh told me. “Now we give the lowest dose we know we can give and it still remains effective,” to minimize side effects. Some researchers have explored new ways to deliver contraception – microneedles, for example, or even microchip technology that allows women to adjust their contraception remotely. (This last idea has raised many privacy concerns.) The Population Council, an NGO based in New York, has been working on a multi-purpose vaginal ring that, in addition to preventing pregnancy, will release an antiviral drug to protect women from HIV , Régine Sitruk. -Ware, a reproductive endocrinologist and contraception researcher at the nonprofit, told me.

But overall, the changes in women’s birth control have been incremental, with more ingredient changes than entirely new recipes. Categorically put, “we’ve had the same offering for about thirty years now,” Heather Vahdat, the executive director of the Male Contraceptive Initiative, told me. And many women remain dissatisfied with the inconveniences and risks that the choices entail. Some experience weight gain, acne or annoying mood swings, or worry about the risk of stroke that can come with hormone-based pills. Others object to the often painful IUD insertion process. Manually inserting a device into the abdomen would likely not be acceptable in other contexts without anesthesia, and yet for female contraception, “we have socialized that into something acceptable,” says Brian Nguyen, an obstetrics and contraceptive researcher at the University of Southern California, told me. Non-hormonal methods such as condoms, diaphragms and spermicides are easy to obtain, but generally less effective than hormonal methods. They can also have their own side effects. And women could certainly benefit from a wider variety of on-demand methods, Vahdat told me – birth control when you have sex, ‘not just when you have sex’ – that would save them the trouble of having to deal with side effects for the whole month, the whole year or ten years.

Over the years, some researchers have argued that significant discomfort and side effects are acceptable for female contraception. After all, women weigh these costs against pregnancy, itself a risky condition that can cause life-threatening complications; men, meanwhile, use contraception to prevent pregnancy with someone else. I asked Vahdat whether the typical side effect profile of currently available female contraceptives would succeed in any of the male methods in studies. “Based on history,” she told me, “I don’t think so.” Several other experts agreed. In 2011, a global study of an injectable hormonal contraceptive for men was halted when an independent safety review board determined that the drug’s side effects “outweighed its potential benefits.” The side effects in question included mood swings and depression, both of which are common in women using birth control. And yet, most participants who stayed in the study said they wanted to keep taking the shot. In recent years, Nguyen has heard more and more men in contraceptive studies citing their female partners’ negative experiences with contraception as a reason for their participation. “Many view the risk to their partner as a risk to themselves,” he said.

Still, strict standards for contraceptive tolerability in men could also raise the floor for female methods. Such crossover advancements are already in the works. Researchers made sure that the topical contraceptive for men was formulated with a dose of natural testosterone, in addition to progestin, the active ingredient that stops sperm production; The idea, experts told me, is to better recapitulate what occurs naturally in men’s bodies, to minimize unnecessary side effects. Many female hormonal contraceptives, meanwhile, rely on a synthetic compound called ethinyl estradiol, which incompletely mimics a woman’s body’s estrogen production — and appears to increase the risk of blood clots. The Population Council is now working on another vaginal ring that replaces ethinyl estradiol with hormones that better suit female biology.

Other conveniences can be more difficult to translate. For example, researchers hope to one day offer men a more easily reversible vasectomy, in which a dissolvable or removable hydrogel is inserted into the vas deferens. But experts told me that temporarily blocking the fallopian tubes is simply more difficult. Furthermore, while sperm is continually produced, eggs are released for fertilization on a cycle that can be difficult to measure and predict, making the side effects also frustratingly difficult to manage, Nguyen told me. Targeted interventions are also more easily delivered to the testes than to the ovaries. And their success is easier to verify: Men have long been able to check their own sperm count with a device similar to an at-home COVID test, but for women there is no parallel, Wang told me. And because it takes months to produce sperm, male hormonal contraceptives may be more forgiving of users who miss a day of treatment — unlike many pills designed for women, which tend to be less flexible, Mitchell Creinin, a contraceptive researcher at UC Davis Health, told me. me.

However, the difficulty of arguing over eggs does not have to mean that options for women are limited. Fertilization cannot occur unless the egg and sperm actually meet. This means that virtually any drug designed to ruin the functionality or motility of sperm could play a role in the female reproductive tract. The options go well beyond spermicide: The Population Council is working on a product that will change the acidity of the vagina to prevent sperm from swimming properly, Sitruk-Ware told me. And Deborah Anderson, an immunologist and reproductive health researcher at Boston University, has been working on a soluble film infused with sperm-blocking antibodies that can be placed in the vagina before sex and that appear to remain at high enough levels to provide contraceptives. 24 to 48 hours, she told me. A number of drugs being tested for men could one day even be marketed to women in some form — including a drug that blocks sperm motility that, experts told me, can also be found in the female reproductive system could be deployed.

With all the attention being paid to men’s contraceptive preferences, some researchers worry that women’s needs will become even more extinct. Jeffrey Jensen, a contraceptive researcher at Oregon Health & Science University, told me that even as grants for male methods continue to get the green light, his team has had to pause work on some female contraceptive projects due to a lack of funding in the In recent years. . “Policymakers think we have checked the box and we can move on,” he said. And Sitruk-Ware said that although researchers at one point had started developing a topical contraceptive gel for women, “donors were more interested in the gel for men.”

Still, the advent of male contraception is unlikely to dampen women’s enthusiasm for using their own methods, Allison Merz, a doctor at UC San Francisco, told me. If these ultra-safe, ultra-effective products for men come to market, they will at least spark more discussions about contraception for women — and raise more questions about why convenience and tolerability weren’t priorities for women from the start.

Leave a Reply

Your email address will not be published. Required fields are marked *