The diaphragm is filled with a small amount of spermicide and inserted in the woman's vagina anytime before sexual intercourse. It fits snugly around the cervix. Once inserted, it forms a tight seal around the cervix. The cervical cap must be left in place at least six hours after sexual intercourse. They allow full personal control over their use.
Side effects are uncommon.
Almost anyone can use them. Diaphragms can be used during menstruation. Diaphragms generally do not need to be replaced for several years. Cervical caps generally do not need to be replaced for 12-18 months. They provide some protection against bacterial STDs, such as chlamydia and gonorrhea.