Should I use a spermicide to help prevent STIs?
No. It was once thought that spermicides with nonoxynol-9 could help prevent STIs much like they help prevent pregnancy — by damaging the organisms that cause the diseases. New research has shown that nonoxynol-9 can irritate a woman’s vagina and cervix, actually increasing the risk of STI infection. Be sure to check the ingredients of any other sex-related products you own, such as lubricants and condoms. Some brands of these products may have nonoxynol-9 added to them. If you are unsure if your spermicide or any other product contains nonoxynol-9, ask your doctor before using it.
