A contraceptive implant is a type of hormonal birth control. In the United States, it’s sold under the brand name Nexplanon. It was previously available under the name Implanon. It releases progestin hormone into the body to prevent pregnancy.
The implant itself is a very small plastic rod about the size of a matchstick. A doctor inserts it into the upper arm, right under the skin.
How Does It Work?
The implant slowly releases a progestin hormone called etonogestrel into the body. Progestin prevents pregnancy by blocking the release of eggs from the ovaries. It also thickens cervical mucus to prevent sperm from entering the uterus.
If you get the implant during the first five days of your period, it’s immediately effective against pregnancy. If the implant is inserted at any other point, you should use a backup form of birth control for seven days.