Male Birth Control Pills do exist but due to a multitude of factors, they aren't safe nor promoted.
1. Males can't get pregnant so the likelihood of them using contraceptive is significantly lower than a Female.
2. Their is a lack of funding for male birth control pills. (Patriarchy? No Customer base? Who knows?)
3. As far as I know some pills have caused liver failure etc.
4. A female ovulates 1 egg a month and has a set number of eggs. It is easier to stop the ovulation process in a female as her body has the existing mechanisms to do so. For a male, it is more complicated as his sperms are constantly being produced. What you are aiming for in males is the reduction of sperm when you make that pill. They tried this way back in the 50s and found that the enzymes involved in sperm production are also involved in other chemical reactions that happen in the liver.
5. There is supposedly tests going on for an injection(?) That will halt sperm production and lasts for 1 year. It's reversible supposedly and safe.
INVENT A MALE CONTRACEPTIVE FOR THE CONVINIENCE AND ROMANTIC EFFECT?!