What Are Spermicides? Spermicide is a substance that kills sperm on contact. Spermicides are available in a variety of different forms including creams, gels, foams, suppositories and films.1 Spermicides are inserted deep into the vagina, near the cervix, with a plastic syringe applicator, or they are inserted with a diaphragm, cervical cap, or contraceptive sponge.3…