Intrauterine devices, implants and rings. Shots, patches and pills. Hormonal vs. non-hormonal. Barrier methods versus non-barrier methods. Thanks to today’s dizzying array of birth control products, many women are able to find a method on the market that works for them.

But the drawbacks are almost as plentiful as the choices: Birth control can be expensive. Side effects range from uncomfortable (cramping, spotting or bleeding, mood swings, nausea) to potentially life-threatening (blood clots, strokes, heart attacks). Even highly effective methods aren’t completely foolproof; women still run a slight risk of pregnancy if they aren’t using a backup method. And since they’re the ones slapping on patches, popping pills and checking monthly to make sure their IUDs are still in place, it’s fair to say women don’t just shoulder the financial and physical burden of birth control – they’re also saddled with most of the responsibility.

In comparison, men – who only have condoms and vasectomies at their disposal – exercise little control over their own reproductive health. And like female birth control, their limited choices aren’t perfect. Vasectomies are permanent. Condoms can be 98 percent effective at preventing pregnancy, but they’re often used incorrectly. And despite their myriad benefits, a recent study published in the Journal of Sexual Medicine showed that only 70 to 80 percent of teenagers use condoms, with usage falling dramatically in older populations.

Aren’t there better – or at least more plentiful – birth control options for men? And if there aren’t, shouldn’t there be?

Many men certainly think so. A study by the Kaiser Family Foundation showed that 66 percent of men were willing to take a birth control pill, whereas 44 percent were up for a birth control shot and 36 percent were interested in the idea of an implant. And researchers across America agree; they’ve been working for years to develop a variety of options – gels, oral contraceptives, shots and more – for males.

If there’s a future for male birth control, it’s a long time coming, experts say. Obstacles include a long development period, financial shortages and a lack of existing regulatory guidelines. Meanwhile, the pharmaceutical industry is wary of supporting new methods of birth control for a variety of reasons – such as lawsuits and a fear of disrupting a lucrative oral contraceptive market. Scientists also say it’s more difficult to block sperm – every milliliter of semen produced has 15 to 200 million sperm in it – than it is to control the ovulation of one egg.

But above all, says Joseph Tash, a reproductive biologist at the University of Kansas Medical Center, it takes a long time to fine-tune any potential contraceptives so there are minimal physical risks.

“It’s essential for any new potential contraceptive agents to have virtually no side effects in order for them to be attractive to [people] who’d want to use it, and in order for them to be commercialized by a pharmaceutical company,” Tash says. “It’s going to have to be at least as good as the best female contraceptives out there.”

Despite the obstacles, the science looks promising. Here’s a peek at a few future options for male birth control:

Vasalgel

Since 2010, the Parsemus Foundation, a nonprofit that supports medical research, has been working on developing a reversible, surgery-free form of vasectomy. In this procedure, a doctor injects a polymer jelly called Vasalgel into a man’s vas deferens – the tube that transports sperm. The gel, which forms a plug that blocks the sperm, can be dissolved with the injection of a separate solution.

According to Elaine Lissner, the foundation’s director and founder of the Male Contraception Information Project, Vasalgel has been successfully tested in rabbits and baboons. She’s hopeful that clinical trials in humans will begin by the end of the year.

“[Vasalgel] has a lot of public support,” says Lissner, who along with the Parsemus Foundation collects public donations and crowdsources funding to support contraception research. (Vasalgel, she says, is a $5 to 10 million dollar endeavor.) “There are about 22,000 men and women on the mailing list now waiting to hear about clinical trials.”

Of course, there are still some final studies to be done, Lissner says. She can’t, for instance, promise Vasalgel’s reversibility until it’s tested in humans. And she’s unsure how long it would take for men to regain full fertility – probably, she says, at least a few months.

Implants

Maybe you’ve seen advertisements for the birth control Nexplanon – a matchstick-sized plastic rod that’s embedded into a woman’s upper arm. The implant releases the hormone progestin, which prevents ovulation. It’s long-lasting and works; doctors say Nexplanon is 99.9 percent effective at preventing pregnancy for up to three years.

The Population Council – a nonprofit that conducts biomedical and public health research – and its partners are developing a one-year implant for men that’s similar in its delivery system to Nexplanon. Called MENT, the device releases a synthetic steroid that resembles testosterone, which affects sperm cell development. Side effects appear to be minimal, with no effect on muscle mass, bone density or libido. However, it’s still in Phase II of clinical trials, and scientists say further research is warranted.

Gels 

The Population Council is also conducting Phase II trials on a variety of contraceptive gels, says Diana Blithe, program director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development’s Contraceptive Discovery and Development program, which helps fund the project. One product that’s currently being studied is a gel-based male hormonal contraceptive containing testosterone and progestin.

When combined, these two separate gels have the potential to inhibit sperm production without causing loss of libido, muscle mass or ejaculation. The gels are rubbed onto the skin. Early studies suggest that the combination has the potential to inhibit fertility while still allowing for a return to normal sperm count after a man stops using it.

Blithe says researchers are in the process of mixing the two gels into a single product,which could be delivered through a pump dispenser or sachets. This could make it less cumbersome than applying both separately.

Pills

The female birth control pill is one of the most ubiquitous contraceptive forms on the market. It makes sense, then, that researchers would try to create a male counterpart.

In 2001, Tash, a professor at the University of Kansas Medical Center, paired up with Gunda Georg, a medicinal chemist from the University of Minnesota. The National Institutes of Health tasked the duo with taking what was originally an anti-cancer drug, lonidamine, and explore its potential as a form of male birth control. One of lonidamine’s side effects was that it blocked the production of sperm, decreasing male fertility. Tash and Georg aimed to refine this trait’s potency, while lessening other undesirable physical symptoms.

The result was a drug called Gamendazole. Although Gamendazole allows for normal ejaculation, the sperm are nonfunctional. Research suggests that Gamendazole causes 100-percent infertility in male rats – an effect that’s reversible after eight to 10 weeks after stopping the drug. It’s also been shown to work in rabbits and non-human primates.

Tash and his team of scientists have met with the Food and Drug Administration to discuss Gamendazole’s efficacy and safety. They hope to soon start pre-clinical safety and efficacy trials that will eventually bring them to their first human clinical trial. However, Tash says, between human clinical trials, examining the data and designing additional testing, it will be a while before Gamendazole hits the market. “I don’t know whether it [will] be five years or 10 years,” Tash says. “Certainly not within the next few years.”

The Parsemus Foundation is also raising awareness about research on a pill called the “Clean Sheets Pill” being done by university scientists in the United Kingdom. Like Gamendazole, this hormone-free method was discovered accidentally from a side effect of blood pressure and schizophrenia medications. The pill’s crux? It relaxes the muscles that create lengthwise contractions along the vas deferens, allowing for orgasm but inhibiting the release of semen.

The Clean Sheets Pill could potentially decrease the transmission of diseases like HIV/AIDS, Lissner says. It’s also a potentially quick-acting pill – meaning it could be taken several hours before sex, like Viagra, and in single doses as needed.

The Clean Sheets Pill has undergone promising pilot studies in animals. Lissner says it suppressed semen by 67 to 83 percent – but only because the drug wasn’t absorbing properly. With tests in an animal model, she says, they could refine the pill. However, she cites a lack of funds, in addition to mixed perceptions over the drug’s function, as reasons why the Clean Sheets Pill hasn’t moved further down the production pipeline.

Originally posted: The Future of Male Birth Control

 

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