Eli5 why are there so many female birth control options for females but only condoms and vasectomies for men?


Was in a discussion about this over dinner last night. My GF has like a dozen options: from pills, to implants and patches. I can either wear a condom or have surgery. I feel like there is always some male pill on the horizon that never manages to come. Why is it so hard to develop something for men but so easy for women?

In: 4006

There’s no hormonal target that stops sperm production entirely without just about completely stopping testosterone, effectively chemically castrating someone.

Women already have a super effective birth control built-in, pregnancy. So many types of birth control simply trick the body into thinking it’s already pregnant.

Women’s bodies have a natural mechanism in place to pause the entire menstrual cycle (which includes releasing eggs). This happens during pregnancy. Female birth control gives women more control of that mechanism.

Men’s bodies do not have a mechanism to stop sperm production. So finding an artificial means to do that AND be reversible is much trickier.

I remember hearing about some gel that would be injected into men; I think it was called Vasalgel. That would be a nice semi permanent solution. Not sure if it didn’t pass FDA approval or if there is some other hold up.

Two main reasons.

First, a woman’s biology has a built-in case where it will prevent pregnancy: pregnancy itself! A pregnant woman’s body won’t normally allow her to get pregnant *again* until the baby’s delivered, so if we hijack that system to trick her body into *thinking* it’s pregnant then we can avoid pregnancy altogether. Men – so far as we’ve found – don’t have any such built-in mechanism that’s as easy to exploit.

The other is side effects. Human reproduction is complicated and any attempt to mess with it is bound to cause side-effects. In women, these issues are known and not great but broadly less dangerous than being pregnant…but men are choosing between side effects with birth control or no *personal* health risk without it. That makes male birth control – especially during trials – a harder sell for men and they have a bad habit of dropping out of trials.

EDIT: My paragraph on side effects is under reasonable question – take it with a grain of salt (or a whole salt lick), as I may be under- or mis-informed there. See child comments like [this one](https://www.reddit.com/r/explainlikeimfive/comments/15mhcfg/comment/jvgeel0) with more information and links to dig through.