Effectiveness for prevention of pregnancy when used correctly is about 89% to 91%[1], but can be used in conjunction with a condom making the contraceptive sponge as effective as any other reversible method of contraception. When improperly applied without the use of a condom its effectiveness is somewhere around 84% to 89%.

Insertion of the sponge requires reaching the cervix, and is generally performed by the woman. Today advertises that intercourse can proceed as soon as the sponge is placed, and up to 24 hours afterward. It has to be left in at least six hours after the final act of intercourse, for a total rated maximum insertion time of 30 hours.

They were introduced in 1983 but were taken off the U.S. market in 1994 after problems were found at the factory where they were produced for Wyeth pharmaceuticals. Wyeth stopped selling the Today sponge rather than pay to upgrade its plant. In 1998, Allendale Pharmaceuticals scraped together money to buy the patents and the complex manufacturing equipment. Tough new FDA standards for manufacturing and record-keeping forced repeated delays, but the Today sponge was finally re-introduced in Canada in March 2003, and in the U.S. in September 2005.

Side effects The Contraceptive Sponge, not being a hormonal contraceptive, has only a few risks, which include the possibility of contracting a yeast infection. There is also the possibility of it tearing, and allergic reactions from the spermicide. Improper use, such as leaving the sponge in too long, can result in toxic shock syndrome.

The sponges are not effective in preventing sexually transmitted diseases. The spermicide nonoxynol-9 used in the contraceptive sponge can actually increase the risk of getting STDs.

Seinfeld
Shortly after they were taken off the market, the sponges became a sort of in-joke on the sitcom Seinfeld, and in the episode "The Sponge", the character Elaine Benes refuses to use a contraceptive sponge (and thus to have sexual intercourse with a partner) unless she deems the interested person "spongeworthy." This happened because her preferred brand was taken off the market, making the sponges worthy of conservation.