Intrauterine device For sure, many people have heard about this method, but few have any idea how it looks and works. That's why it's the coil in the animation that is presented☝🏻 It is an intrauterine contraceptive that works for 5-12 years (if necessary, you can remove the spiral). Yet, the method has its own disadvantages. The spiral works by stimulating the production of mucus, which prevents the penetration of sperm cells into the uterine cavity. Also, the coil stimulates the release of substances that prevent the egg from attaching to the uterine wall.