Does the IUD lose effectiveness as years go by?

No. It is made of a kind of plastic that is impregnated with various kinds of contraceptive. The dose is very low and is released very slowly into your body over the length of time you have it. It is not more effective when you first get it. Eventually the effectiveness will wear off, but there have been extensive tests carried out on these implants and the lifespan is worked out to make sure it won't expire before you get it removed. Unlike oral contraceptives you don't have to worry about stomach upsets and I believe there are fewer conflicts with other medications than with OCP. Hope this helps. L