Spermicide is a form of contraceptive that kills or immobilizes sperm, keeping them from entering the uterus. Many spermicides contain the active ingredient nonoxynol-9, which breaks down sperm membranes. It often is in the form of gel, cream or foam, and it is available over the counter.
While spermicide can be used alone, it most often is used in conjunction with a barrier method of birth control, such as a diaphragm, sponge, cervical cap, latex condom or female condom. It is applied either to the contraceptive device or inserted directly into the vagina before intercourse. Some spermicides are effective immediately, and others must remain in the vagina for certain lengths of time prior to intercourse. It is only effective for one hour after insertion; an individual must apply more if more than an hour has passed and prior to another occurrence of intercourse.
According to the Mayo Clinic, spermicide is about 71 percent effective at preventing pregnancy when used alone. This rate increases when it is used consistently and correctly. It is most successful when used in addition to another method of birth control.
There are some possible side effects to using spermicide. It can cause vaginal or penile irritation. There also is the possibility of increased urinary tract infections for women.
One does not need a prescription for spermicide, and it is widely available. It also is portable and relatively inexpensive. Additional advantages include the fact that is does not affect a woman's hormones, it can be used during breastfeeding, and it is a reversible method of contraception. Spermicides might also increase lubrication during sexual intercourse.
There are multiple disadvantages to choosing this method of contraception. It can be messy to use and must be applied before every episode of sexual intercourse. Spermicide also might leave a bad taste during oral sex. If it does cause vaginal or penile irritation, this can make it easier to contract HIV or other sexually transmitted diseases. Additionally, when used alone, the failure rate for preventing pregnancy is high compared to other methods of contraception.
Spermicide might be a practical, inexpensive and convenient option for some individuals. Spermicide alone might not be the most effective method of birth control, but it is more effective than using no form of birth control at all. It does not protect against sexually transmitted diseases, so another form of protection should be used if there is a risk of contracting a disease.