It is a small, soft, flexible plastic rod measuring 4 cm in length and 2 mm in diameter that contains 68 mg of Etonogestrel. It is inserted just under the skin on the inner side of the non-dominant upper arm, acting in two shapes:

- Prevents the release of the ovum
- Produces changes in the cervix that make it difficult for semen to enter the uterus 

Protects against pregnancy for a period of 3 years. 
While using Implanon your menstrual bleeding may change and stop.