A male contraceptive medication would have to work through a fundamentally different mechanism than female birth control, requiring changes to sperm or sperm production. I myself would be extremely skeptical until it had been on the market for a long period of time. This is less a skepticism of science and more of a skepticism of the pharmaceutical industry (particularly in the states).

Edit: After looking into the mechanisms of the up and coming methods (primarily hormonal) that have been in the news I think my conclusion was a little hasty. I think long term risks are likely very low or at least comparable to women’s birth control.