A contraceptive implant is an implantable medical device used for the purpose of birth control. The implant may depend on the timed release of hormones to hinder ovulation or sperm development, the ability of copper to act as a natural spermicide within the uterus, or it may work using a non-hormonal, physical blocking mechanism. As with other contraceptives, a contraceptive implant is designed to prevent pregnancy, but it does not protect against sexually transmitted infections.