These include vaginal pessaries (e.g. Patentex Oval, Kolpotex) with a spermicidal substance, which damages the sperm and, by creating a rich foam, mechanically prevents it from getting into the uterine cavity, and hence fertilization.
This method is non-invasive and inexpensive. These preparations improve the lubrication of the vagina.
Cons: Spermicides have low contraceptive efficacy (with failure rates ranging between 5 and 20, meaning that within a year of use of these preparations five to twenty women in a hundred will experience an unintended pregnancy).