For more than half a century, the birth control pill has only been available to women, but with a recent scientific breakthrough, scientists claim we are closer to the male birth control pill than ever.

Researchers in the U.K. made a peptide compound that can penetrate sperm cells, then fertility scientists in Portugal, who are collaborating with the U.K. scientists, targeted the specific protein responsible for sperm's ability to swim and turned it off, reports The Telegraph. “The results are startling – and almost instant. When you take healthy sperm and add our compound, within a few minutes the sperm basically cannot move," John Howl, lead researcher and professor at Wolverhampton University, told the The Telegraph, 

So far, the scientists have tested bovine and human sperm, with live animal tests set to begin within three years, reports The Telegraph. Howl told Yahoo that he sees "tremendous potential" for male birth control, emphasizing the high rate of unplanned pregnancies.

And there is a demand. A Kaiser Family Foundation survey showed that 66 percent of men were willing to take a birth control pill, 44 percent would get a shot, and 36 percent were interested in an implant.

Previously, the major approaches to male contraception have been an injection blocking sperm emissions, an inhibitor preventing sperm from swimming, and immunosuppressant drugs causing sperm to mature with deformities that prevent pregnancy – all of which have not hit the market mainly because of a lack of funding.

Herjan Coelingh Bennink, global executive vice-president in pharmaceutical company Organon's reproductive medicine program until 2000, told Quartz about the lack of support for male contraception within the company at the time: “At board level it was only middle-aged white males. I tried to explain how important it could be, but they never got further than saying to each other, ‘Would you do it?’ ‘No, I wouldn’t do it.’ It was not considered male behavior to take responsibility for contraception.”

Big Pharma's interest in male birth control piqued between 2003 and 2004, when researchers conducted a large clinical trial giving nearly 300 men progestogen implants and injections of a testosterone product, reports Quartz. These were the results:

"For almost nine-tenths of the men on the hormonal contraceptive, sperm counts fell below the million mark, and once the trial was over they all recovered normal fertility after around four months. But not everything was ideal. More men taking hormones suffered ‘adverse events’ like acne, sweating, and effects on weight, mood and sex drive than the placebo group. Some of these were more serious and even life-threatening, including one attempted suicide."

Women have been living with birth control side effects for decades. 

Adverse side effects have not deterred the development and availability of the birth control pill for women. As Broadly points out, the adverse side effects of hormonal birth control on women has historically been hidden. But in September, a Danish study published in JAMA Psychiatry provided evidence supporting the correlation between the use of birth control and a diagnosis of clinical depression, confirming the lived experience of women over the past 50 years.

In contrast to the female birth control pill, the male contraceptive developed from this breakthrough would be non-hormonal, possibly taking the form of a pill, implant or nasal spray, although it's "too early to say," Howl told The Telegraph.