How It Prevents Pregnancy
When a birth control implant is inserted, it slowly releases progesterone. This prevents pregnancy in two ways:
- The progesterone gradually thickens the mucus in the cervix, which stops the sperm from swimming toward the uterus where it can interact with the egg. When the sperm fails to reach the uterus, there can be no fertilization.
- The second mechanism is the prevention of ovulation and/or stopping the eggs from leaving the ovaries. If no eggs are produced, there can be no pregnancy even if the sperm reaches the uterus.
The birth control implant is a 1.6-inch thin rod that contains approximately 68 mg of progestin. Once it is inserted, the implant releases an average of 62 mcg each day. This goes down to 35 to 45 mcg per day the end of the first year and 25 to 30 mcg by the end of the third year. The birth control implant is recommended for use up to 3 years.
It is important to understand that once inserted, the birth control implant does not work right away. Generally speaking, women have to wait at least five days after their last period before it is fully effective. If birth control is required during this time, it is recommended that women use a form of barrier contraception, such as a condom.
How Long It Lasts
The effect of the birth control implant lasts anywhere from three to five years. It is recommended that women should get another implant after 36 months if they do not wish to get pregnant. It is important to remember when the implant was inserted so that you know when it is time to have it removed or replaced. The removal procedure is fairly simple and can be performed in the doctor’s office. The doctor will numb the skin. A small incision is made under local anesthesia, and the implant is removed.