Implanon® has been FDA approved for over three years and remains underutilized
as one of the most effective hormonal contraceptives ever developed. It
is a flexible plastic rod the size of a matchstick that is inserted under
the skin on the inner side of a woman’s upper arm. Implanon®
contains a progestin called etonogestrel, also found in some birth control
pills. Implanon® prevents pregnancy for three years by several mechanisms
of action: Inhibiting ovulation, altering cervical mucus to reduce sperm
migration, and changing the inner lining of the uterus so it’s unreceptive
to egg implantation. The chance of getting pregnant is very low (less
than one pregnancy per 100 women who use Implanon® for one year).
Because Implanon® contains only progestin and provides up to 3 years
of protection without daily, weekly, or even monthly action, it is well-suited for:
- Women who wish to or need to avoid estrogen (e.g. minimizes attributable
side-effects of nausea, headaches, and blood clots)
- Teens who find adherence to a contraceptive regimen difficult
- Current Depo-Provera® users looking for greater convenience & avoiding
adverse effects on bone density
- Healthy adult women who desire the convenience of long-term protection
- Women who are breastfeeding
The most common side effect of Implanon® is a change in a woman’s
menstrual periods. While menstrual periods may be irregular and unpredictable,
there is usually less bleeding, and some women will have no periods. A
few women also gain weight.
Implanon® must be removed after three years when the implant runs out
of hormones. It also can be removed anytime beforehand if the woman wants
to become pregnant, where the ability to conceive returns quickly. In
conclusion, most women are satisfied with Implanon®, citing its long
duration, high efficacy, and convenience.