When it comes to men’s options for birth control, they really only have two choices: wear a condom or get a vasectomy. While the number of options available to women has increased dramatically in recent years, nothing has really changed for men. So why is that?

The video below from Science Insider explores the answer to this question. As you’ll see, it’s not due to a lack of trying—scientists have been at work on developing a safe and effective male contraceptive for decades. Despite a lot of promising starts, though, they just haven’t had a lot of success yet.

Part of the reason for this is because researchers have found that, in trying to reduce sperm counts to very low levels, it typically produces a lot of side effects. Of course, any hormonal birth control is going to produce side effects, so it’s unrealistic to expect a product that would be free of them. If and when a hormonal male contraceptive makes it to market, male consumers will have to accept that certain side effects will come with it (just as female consumers have done for decades).

However, another reason we don’t have male birth control yet is lack of funding—pharmaceutical companies just haven’t invested in it the way they have in female-controlled methods of contraception. That said, there are some promising lines of research underway, which you can learn more about in the video below.