The Female Condom Making Your Choice Spermicides Like condoms, spermicides are widely available. They come in foam, suppositories, cream, or jelly. For best effectiveness, all of these forms must be used with a condom, diaphragm, or cervical cap. How they work.
Spermicides contain a chemical that kills sperm.
When you insert spermicidal foam or suppositories into the upper part of your vagina, the medication kills most sperm and helps prevent those that survive from entering your cervix. A diaphragm or cervical cap will hold spermicidal creams or jellies in place over the cervix. You can also use them to coat a condom. Many brands of spermicide now contain nonoxynol 9, a chemical that helps protect against some types of STDs. Spermicidal foams and suppositories have a failure rate of about 21 percent.