Contraceptive implants are small, flexible rods that are placed under the skin of a woman's upper arm. They release hormones, typically progestin, to prevent ovulation and make it harder for sperm to reach an egg. The implants can provide effective birth control for up to three to five years, depending on the type used. The procedure to insert a contraceptive implant is quick and usually done in a doctor's office. After insertion, there is minimal maintenance required, making it a convenient option for many women. Side effects may include changes in menstrual bleeding, headaches, and mood changes.