How it works: The Today Sponge, the only brand available, is a plastic foam sponge that contains spermicide. It covers the cervix while also continuously releasing spermicide. You know it from Seinfeld.
Success rate: Among women who have never given birth, nine out of 100 of them will become pregnant using the sponge. If these same women do not always use it correctly, 16 out of 100 will become pregnant. It will not impact your hormones.
Pros: You can buy it over the counter, and you can have sex as many times as you like during the first 24 hours of wearing it. It's also included in the Affordable Care Act's free birth control mandate.
Cons: It does not protect against STIs, and it can be expensive bought over the counter ($17 for a package of three). Plus, it can be difficult to insert or cause messy or dry sex.
