How effective are expired birth control pills?

Answer 1

Like all medication, when it expires, it becomes less effective (and increases in its ineffectiveness as the time goes on). It's not easy to give a percentage as to how effective compared to non-expired pills, but if using expired Birth Control is your only option, I would use it with a condom or some other non-hormonal birth control to make sure you don't get pregnant. Otherwise, the likelihood of pregnancy will increase.