Ovulation may also be inhibited. The IUD is a small, copper-coated device which sits inside the uterus. It works by destroying sperm before they fertilize the egg. Depending on the brand, the IUD can remain inside a woman's body for up to 10 years. Good Condoms are worn by either the man or woman, and work by preventing sperm from entering the vagina.
Condoms are more effective if used in combination with a spermicide.
The female condom is a polyurethane sheath placed inside the vagina. It has two flexible rings at each end of it. It is inserted into the vagina with its closed end high inside and the larger, open end just outside the labia. The male condom is a latex sheath worn over the penis. It works by killing sperm.