Contraceptive sponges combine a barrier with a spermicide. An occlusive pessary is generally used in combination with spermicide as a contraceptive. The spermicide Nonoxynol-9 has been claimed to reduce the likelihood of STI transmission. The condom does not contain spermicide. Condoms may be combined with other forms of contraception (such as spermicide) for greater protection. Secondly, the sponge contains spermicide. The water is used as a mechanism to activate the spermicide inside the sponge. Some people are allergic to the spermicide used in the sponge. The current recommendation is still for all diaphragm users to use spermicide with the device. Copper acts as a spermicide within the uterus. They work by blocking access to and holding spermicide near the cervix. Menfegol is a spermicide manufactured as a foaming tablet. The sole goal of spermicide is to prevent fertilization. The product contains no spermicide and thus cannot be used to prevent pregnancy. Spermicide use, independent of sexual frequency, increases the risk of UTIs.