Male birth control, like death, is always just around the corner.

In 2014, the hope was that Vasalgel, a non-hormonal polymer gel that can be injected into the vas deferens, would hit the market by 2017. But the Parsemus Foundation, the non-profit organization funding Vasalgel, has since revised that projection to 2018, pending successful human trials and “public support.”

Now, Kevin Eisenfrats, the young co-founder and president of the biotech startup Contraline, is racing them to the finish line with a gel-based male contraceptive called Echo-V. He claims that his company will finally turn reliable male birth control from a distant inevitability into a reality.

“We think it will be five years until we’re on the market,” he told The Daily Beast, adding that it could be available as soon as 2020 if their timetable unfolds smoothly.

Medically speaking, Echo-V is similar to Vasalgel. Both are gels injected into the vas deferens that block sperm while allowing other fluid to pass through. Instead of being trapped inside the small sperm-transporting duct, the blocked sperm are “degraded naturally by the body’s own immune system,” according to the Echo-V FAQ. Both products aim to be longer-term contraceptive solutions.

But whereas Vasalgel requires a tiny incision prior to the injection, Echo-V will use an imageable gel along with ultrasound technology researched by the University of Virginia (UVA) to guide the injection without an incision—a technique that Eisenfrats jokingly compares to “taking a strand of spaghetti and injecting it with a viscous polymer.” The imageable gel will also simplify check-ups after the initial injection.

Both Vasalgel and Echo-V are non-hormonal and potentially reversible with a second injection that flushes out the gel. Proving that reversibility has become the holy grail in this emerging field; otherwise, gel-based solutions would only compete with vasectomy.

In a March blog post, the Parsemus Foundation noted that reversibility has “so far been elusive in animal studies.” A newly-published Vasalgel study demonstrated reversibility in rabbits but similar tests in baboons and dogs have been less successful.

Echo-V is only now entering animal trials but Eisenfrats is confidently predicting that Contraline’s technology may produce more promising reversibility results. He’s also hoping for a shorter path to humans given his team’s prior experience with the FDA-approval process.

“We’ve gone through the FDA before, we know the path to market, and we’re following all of the guidelines and protocols for the FDA even right now,” he told The Daily Beast.

In an email to The Daily Beast, Parsemus Foundation executive director Elaine Lissner complimented Contraline’s “technique advances” but noted that her organization is currently ahead in animal research, working on their reversibility issues, and “moving full speed ahead” toward a clinical trial for Vasalgel as a vasectomy alternative without the promise of reversibility.She also tempered expectations for when Vasalgel would make it to market.

“We are aiming for first-country approval within three years,” she wrote. “2018 has been quoted a lot in the press, but that is optimistic at this point.”

Eisenfrats has nothing but praise for the Parsemus Foundation but he prefers the private route. The 22-year-old entrepreneur is a UVA graduate who wrote his college admissions essay on male birth control. His co-founder, UVA reproductive cell biologist Dr. John Herr, is a biotech veteran. Just last month, their company was accepted into the Y Combinator Fellowship Program, which is run by a powerful Silicon Valley startup accelerator that distributed seed money to future giants like Airbnb and Reddit.

Contraline has all of the ingredients to become a hot startup, with all of the risks and benefits that entails.

The Parsemus Foundation, on the other hand, is “relying on public support” to get Vasalgel to market, as they note on their website. The organization is soliciting direct donations to fund trials and may turn to a large crowdfunding platform in the future. They are aiming for “affordable pricing and wide availability.”

Whenever and however it arrives, gel-based male birth control would be monumental. Given the range of side effects that women experience when using oral contraceptives and IUDs, a non-hormonal male contraceptive could revolutionize not just medicine, but sex itself.

According to various estimates, the size of the global contraceptives market is approaching $20 billion, largely driven by pills and devices aimed at women. As Priceonomics reported, major pharmaceutical companies are not likely to even get out of bed for the relatively small male contraceptive market, especially because new options would “cannibalize their existing products.”

In other words, the pharmaceutical industry currently has a vested interest in maintaining the birth control status quo, with women bearing the ultimate responsibility for preventing unintended pregnancy.

Technologies like Echo-V and Vasalgel could alter the long-term dynamics of that market but, perhaps more importantly, they would introduce a new equation into the intimate calculus of pregnancy prevention. At present, men’s options—condoms or a vasectomy—are almost as narrow as the vas deferens itself.

According to the CDC, condoms have a failure rate of 18 percent during “typical use,” which means that if 100 women start relying on condoms for a year, 18 of them will experience an unintended pregnancy. The condom failure rate drops to about 2 percent for couples who use condoms perfectly, but that’s still nowhere near the level of protection provided by an IUD or a birth control implant.

Unlike condoms, Echo-V and Vasalgel do not protect against sexually transmitted infections, but if they turn out to have provably low failure rates in humans, it’s easy to imagine their possible applications.

Long-term couples might choose a polymer gel injection instead of an IUD, or to feel more comfortable removing condoms from their routine. Single male condom users might get the injection as an added layer of security. And married men, like one Contraline investor, might seek out Echo-V as a vasectomy alternative.

That investor, a married father who had reached his target number of kids, reportedly told Eisenfrats: “A week ago I had a conversation with my wife: ‘Are you going to get an IUD or am I going to get a vasectomy?’”

Widely-available male birth control is still a ways off. Eisenfrats told The Daily Beast that his company would focus first on “early adopters,” like men who are considering a vasectomy anyway. Then they would move on to “late adopters” like married men who do not yet have children.

The demand, meanwhile, is already here. Vasalgel has generated enormous public interest. And Eisenfrats says that men are already signing up on the Contraline website, volunteering themselves to be “pioneers of male birth control,” as the company playfully puts it.

“I’ve had guys email me for months now on a weekly basis asking to be in clinical trials,” he said.

Those trials won’t happen for a while longer yet but rest assured, male birth control is coming… eventually.