Every year, new research seems to indicate we're getting closer to creating better male birth control. Some scientists are working to make this a reality, however there's a long way to go before a male-based contraceptive hits the U.S. market.

Why create more male birth control methods?

Often, the responsibility of pregnancy prevention falls on women -- despite the fact that it takes sperm and an egg to make a baby. There are many Food and Drug Administration (FDA) approved birth control methods women can choose from. Women can swallow daily birth control pills, opt for an intrauterine device (IUD), use the patch, or get a shot, among other things. Men, on the other hand are limited to condoms and vasectomies, which some argue make men feel emasculated and "neutered." Thus, many would like to see the responsibility for contraception to be shared equally between men and women.

Who has developed better forms of male birth control?

Last month, Vice Motherboard published an extensive report on two research teams hoping to make male birth control available to the masses. 

In the late 1970s, a professor named Sujoy Guha came up with the Reversible Inhibition of Sperm Under Guidance (RISUG) in India. The method, which was first tested on rats, entails injecting a polymer created by Guha into the vas deferens, which is the passageway from the testes to the penis. This makes the sperm less resilient as they travel to the egg, thus making them incapable of fertilization. The injection can also be flushed out to restore sperm fertility should a man decide he wants to conceive children at any point.

But you won't find RISUG in America anytime soon, at least in its current state. In the early 2000s, a World Health Organization (WHO) team visited Guha's lab in India and rejected the RISUG production process, saying Guha's research didn't fulfill “international regulatory requirements” for new drug approval. WHO took issue with the fact that Guha concocted the polymer in his own lab, which they believed needed to be modernized. Meanwhile, Guha faced some pitfalls trying to get RISUG approved in India, with the Indian Council for Medical Research calling for more research to be done. As Vice pointed out, India's union health officials abandoned RISUG in 2002 due to reported complications in phase III clinical trials, including scrotum swelling. At present, RISUG is currently undergoing clinical trials in India.

Though RISUG has had its fair share of skeptics, lots of men want to partake in the clinical studies or want RISUG, according to Ronald Weiss, a Canadian vasectomy surgeon and member of the WHO team that traveled to Guha's lab.

“If you’re looking for the better mousetrap, this is it,” Weiss said in an interview with Wired in 2011. “I have received emails from men all over the world kind of champing at the bit to get RISUG.”

Several years ago, the medical research nonprofit organization Parsemus Foundation paid $100,000 to acquire international rights to RISUG. The Parsemus Foundation is currently developing Vasalgel, is a slight variation of RISUG. In the Vasalgel procedure, a gel is injected into the vas deferens, "forming a a semi-solid plug that blocks sperm," according to Parsemus's website. The gel serves as a filter and prevents sperm-flow. 

Why Vasalgel and RISUG aren't available in the U.S.

There are several reasons why RISUG is not yet available -- not including the thorny cultural question of whether men will actually use it.

Since RISUG clinical tests were conducted overseas, the FDA won't consider the results from Guha's studies. The testing done in India would have to take place in the U.S. and have larger samples. Even if the FDA said humans were ready to be tested, it would cost millions of dollars. 

Funding for more expansive studies is also a barrier to male birth control. The Parsemus Foundation depends on public support to make Vasalgel a reality in our country. Initial rabbit studies have shown Vasalgel to work as well as RISUG, however it was only a year-long study, so more research will be necessary for Vasalgel to get credibility in the United States. Parsemus Foundation's Director of Family Planning, Kellie Sloan, told Vice that gaining financial support for the organization's research can be challenging. 

"The science of contraception for men is less advanced, as is the proof of concept for men using contraception in the poorest countries of the world," Sloan told the publication.

Dr. Sabatino Ventura, a male birth control researcher in Australia, said last year that it's hard for some to take male birth control efforts seriously as a host of effective female methods already exist.

"You’ve already got a good female contraception, so people don’t think we need a male equivalent," Dr. Ventura said. "It’s more like: ‘Oh, that would be handy, but we could probably do with curing a whole lot of other diseases beforehand.’"