The contraceptive implant is a single progesterone rod. It has a very low dose of hormone to minimize side effects. The main side effect is periods become irregular and unpredictable but usually with less bleeding and fewer bleeding days. It is effective for 3 years but if desired it can be removed before the three years is over and it is rapidly reversible. The implant has the lowest failure rate of any of the birth control method, lower even than tubal ligation.
The rod is smaller than a match stick. The active ingredient is etonogesterol, a progesterone, and it is slowly released over the 3 years the device is active. The rod is placed in the inside of the upper arm between the elbow and the underarm. It is not painful to place or remove; it hurts as much as any injection. At the end of the three years, a new one can be inserted in the same location if longer contraception is desired.
There are two versions of the implant available in the US: Implanon and Nexplanon. They are made by the same company. Nexplanon has some minor improvements and will be replacing Implanon completely.
Because of the very low dose of hormone, this method has very few side effects. It does not cause any significant weight gain or acne. The main side effect is the changes in menstrual patterns. Women on the implant can expect to have irregular and unpredictable bleeding. Overall you can expect fewer overall bleeding days and the bleeding days that are present tend to be lighter. You just won’t be able to predict when the bleeding will occur. Most women will experience less and less bleeding over the life of the product, a trend towards amenorrhea. Unlike the contraceptive shot , Depo Provera, the implant does not suppress estrogen levels. This avoids side effects such as mood swings, hot flashes, and loss of bone mineral density.
This is a popular contraceptive for women who desire a long acting reversible contraceptive method. It has a lower failure rate than the IUD and is much less painful going in than the IUD. Because it is not in the uterus, there is no worry about it causing or aggravating a pelvic infection as can happen with the IUD. The implant has advantages over the Depo Provera (contraceptive shot) in that it lasts 3 years and has much less hormone and therefore fewer side effects. It has about the same hormone exposure as the Mirena IUD (5 year IUD). It has advantages over the pill, patch, or ring as there is no need to worry about forgetting when it is time to take or place the birth control device.