Proposed Male Birth Control Options Include Below-the-Belt Injections and a 'Clean Sheets Pill'

This story is part of a partnership between MedPage Today and VICE News.

Scientists are studying a new contraceptive injection that might become the male version of "the pill," but this isn't their first crack at solving the male birth control riddle.

It's not even the only male contraceptive being studied right now. Scientists are also studying a substance derived from a shrub and something called "the clean sheets pill," which is pretty much exactly what you think it is.

Here's what you need to know:

The male contraceptive making waves on the Internet this week is called Vasalgel, and it's being developed by the nonprofit Parsemus Foundation.

It's a one-time polymer injection to the vas deferens (an area in the scrotum between the testicles and the urethra) that works as a plug by blocking sperm from the ejaculate fluid and allowing it to instead be re-absorbed by the body — kind of like a vasectomy. But unlike a vasectomy, the goal is to make the infertility reversible with a second injection that would dissolve the polymer.

"Until reversal is sure, it's not going to be for men who want children later unless they also freeze their sperm," the Parsemus Foundation's executive director, Elaine Lissner, said. "When it becomes really revolutionary is if younger men can use it for child spacing. Say you get it when you turn 18, but you don't want children until you're 28 or 38. That would be amazing. That's what we're hoping for."

Scientists developing Vasalgel at the Parsemus Foundation have tested it in rabbits, baboons, rhesus monkeys and dogs. The foundation hopes to start human trials later this year, and to have 32,000 men on their mailing list for trial updates, Lissner said.

"It works exceedingly well," Lissner said. "In fact, the trouble is trying to get the darn stuff out."

The rabbit trial, published last week, showed that no sperm got through the polymer plug, and it was successfully reversible with a second injection. But the researchers have found it wasn't as reversible in the larger animal studies, perhaps because the vas deferens is less "stretchy" to begin with, making it harder for the second injection to dissolve the polymer, Lissner said.

If this contraceptive doesn't make it to market, there are other potential male birth control drug options being studied.

Gendarussa is a drug is derived from an Indonesian shrub, and it's thought to affect the enzymes that normally help the sperm penetrate the egg. It's approaching phase III trials in Indonesia, but would need to repeat its phase I and II trials to get approval from the US Food and Drug Administration.

Eppin is another drug that's thought to replace a protein that binds to sperm cells' surface, keeping it from swimming until an enzyme removes it. The Eppin drug can't be removed by the enzyme and therefore never allows the sperm to swim. They will undergo toxicology tests before seeking to begin clinical trials, according to the nonprofit Male Contraception Initiative.

And then there's the "Clean Sheets Pill." In theory, men would take this a few hours before intercourse to keep targeted muscles from pushing semen forward. The man can still have an orgasm, but as the name suggests, the sheets are clean because there's no ejaculate fluid. The researchers are looking for funding to study the drug in rams, according to the Male Contraception Initiative.

But the hunt for male birth control isn't new. Scientist started searching for a male contraceptive soon after the arrival of the female birth control pill in the 1950s and 1960s, and they hoped to use some of the same concepts. Hormones in female birth control — usually estrogen, progestin, or both — trick the body into thinking it's pregnant because pregnant women don't ovulate. Scientists hoped to use hormones to temporarily block fertility in men, too, but found it wasn't that simple.

"With a guy, there's no natural state when he stops producing sperm," Aaron Hamlin, executive director of the Male Contraception Initiative, said. "When you try to use hormones, it takes an awful lot of testosterone to do that. And it comes with side effects: Depression, acne, all things associated with lots of testosterone."

Men are thought to be less accepting of side effects than women because they can't get pregnant, biochemist Doug Colvard, of CONRAD, a nonprofit that seeks to improve global reproductive health.

For instance, women have long accepted the blood clot risk that comes with taking hormonal birth control pills because that risk is even considerably greater during pregnancy. It's part of a biological mechanism to prevent excessive bleeding during pregnancy and birth.

"I think a lot of men are looking for more reproductive control, but don't want to repeat what women have had to put up with with hormonal methods," Lissner said, nothing that Intrauterine Devices (IUDs) are becoming increasingly popular and don't always have hormones. "And they shouldn't have to because we can do better now."

Still, there's a false narrative that men wouldn't use a birth control pill or device, Hamlin and Lissner said. Lissner said the 32,000 members on the Vasalgel mailing list suggest otherwise. The Parsemus Foundation also lists several surveys that show between 25 percent and 83 percent of men said they would use some form of male contraceptive drug or reversible procedure if it were available.

Perhaps as a result of the idea that men don't want these things, funding for research has been a recurring problem over the years, Colvard said. Big pharmaceutical companies, including Organon international, Schering AG, and Wyeth (none of which still exist under these names because they merged with other companies) were working on male contraceptive pills, gels, and implants a decade ago, but they've all since pulled out of the pricey research.

"There's way more money to be made in treating disease than in preventing pregnancies," Colvard said.

According to Hamlin, more funding money is going into an effort to find birth control options for cats and dogs than for human males. Lissner said she wasn't so sure about this fact, but agreed that funding is indeed an issue even for Vasalgel, which Parsemus is trying to fund as a "social venture" company within the foundation that makes just enough money to stay afloat without begging for money.

"It's easy enough to get $100,000 to do a pilot study on rats," she said. "Once you show it works on rats, where do you go from there? Where do you get the million plus dollars a year to get to the next steps?"

Photo via Flickr