Two Sticks - One Under The Skin, On Implanted
Depo-Provera, approved by FDA in 1992, is injected by a health professional into the buttocks or arm muscle every three months. Depo-Provera prevents pregnancy in three ways: It inhibits ovulation, changes the cervical mucus to help prevent sperm from reaching the egg, and changes the uterine lining to prevent the fertilized egg from implanting in the uterus.
The progestin injection is extremely effective in preventing pregnancy, in large part because it requires little effort for the woman to comply: She simply has to get an injection by a doctor once every three months.
The benefits are similar to those of the minipill and another progestin-only contraceptive, Norplant. Side effects are also similar and can include irregular or missed periods, weight gain, and breast tenderness.
What is Norplant?
Norplant, approved by FDA in 1990, and the newer Norplant 2, approved in 1996, are the third type of progestin-only contraceptive. Made up of matchstick-sized rubber rods, this contraceptive is surgically implanted under the skin of the upper arm, where it steadily releases the contraceptive steroid levonorgestrel.
The six-rod Norplant provides protection for up to five years (or until it is removed), while the two-rod Norplant 2 protects for up to three years. Norplant failures are rare, but are higher with increased body weight.
Some women may experience inflammation or infection at the site of the implant. Other side effects include menstrual cycle changes, weight gain, and breast tenderness. Another important but less obvious change may be loss of bone mass.