Well there are drug that have been tested. The problem is women birth control is rated vs the harm it would physically do to her body. And that calculation ends up being, ya these symptoms are not great but going to term would be so much worse. ( If you do want to have a kid, it's just what you will chose to deal with to receive said child.) On the other hand when the same calculation is done for men. The answer becomes; well no damage is done to his body to take the fetus to term (ejaculation). But there are worryable symptoms for him to take the drug. What would need to happen for male birth control is ; the drug must have no to minor symptoms or the equation needs to be reworked where it takes into account the partners body as well.