The birth control shot is a hormonal method of birth control. It is also known as Depo-Provera or DMPA.
The birth control shot is an injection of the hormone progestin. It prevents pregnancy for up to three months. DMPA was approved by the Food and Drug Administration (FDA) in 1992. Since then, it has been tried by 22 percent of American women. The birth control injection is a highly effective method with approximately six of 100 women becoming pregnant in a year of typical use.
The birth control shot contains a synthetic version of progestin called DMPA (depot medroxyprogesterone acetate). This hormone blocks ovulation. Ovulation is the release of an egg from the ovaries. Without ovulation, pregnancy cannot occur.
Progestin also thickens the cervical mucus to block sperm.
Each birth control shot lasts for 12 weeks. After 12 weeks, you must get a new shot. If you don’t, you are at risk for pregnancy and should use a backup method of birth control if you are sexually active.
Make an appointment with your doctor to discuss what method of birth control is best for you. You need a prescription to get the birth control shot.
Your doctor will administer the shot during your exam. Start using the shot immediately if you are reasonably sure you are not pregnant.
If you get the shot within the first seven days of starting your period, you are protected immediately. Otherwise, you need to use backup protection for the first week. You are also protected immediately if you get the shot within three weeks of giving birth.
You will need to return to the doctor’s office every 12 weeks for an injection. The birth control shot is typically given in the upper arm or buttocks.
The Depo-Provera shot is a highly effective birth control methods. According to Planned Parenthood, women who use it correctly have a less than one percent risk of pregnancy. If women wait too long between shots, the failure rate increases to six percent.
If you are more than four weeks late for your shot, your doctor may require that you get a pregnancy test before administering a shot.
The primary benefit of the birth control shot is its simplicity – you can get a shot every three months and you don’t have to worry about birth control. The shot also provides a level of privacy not available with other birth control methods. There is no evidence of birth control on your body. You have no supplies to carry around.
Unlike many other hormonal methods, the birth control shot can be used by women who cannot take estrogen. It is also an excellent option for people who are worried about remembering to take hormonal oral contraceptives (“the pill”) correctly on a daily basis.
The birth control shot has several disadvantages. They include:
- no protection against sexually transmitted infections (STIs)
- possible spotting between periods
- irregular periods
Most women taking the shot get progressively lighter periods over time. Many end up stopping their periods entirely after one year of after one year of use, which is perfectly safe. However, some women do get longer, heavier periods.
Less common side effects of the shot include:
- change in sex drive
- weight gain in teens who are already overweight
- sore breasts
- hair loss
Women who use Depo-Provera may also experience temporary bone thinning, which increases the longer you use this form of birth control. Bone thinning will stop when you stop using the shot. Doctors recommend taking supplements and eating foods rich in calcium and vitamin D to help protect your bones. There is no evidence that this temporary bone thinning causes health problems later in life.
Though rare, serious side effects can occur. You should seek immediate medical attention if you begin experiencing the following symptoms while using the shot:
- major depression
- pus or pain near the injection site
- unusual or prolonged vaginal bleeding
- yellowing of the skin and/or eyes
- breast lumps
- migraines with aura (a bright, flashing sensation that precedes migraine pain)