Depo-Provera is a reversible method of prescription birth control. Also known as DMPA, Depo shot, Depo, or the birth control shot, this progestin-only contraceptive prevents pregnancy for up to three months with each shot.

Depo-Provera slowly releases a progestin known as medroxyprogesterone acetate which must be taken every 13 weeks. It works by preventing ovulation and thickening the cervical mucus. This prevents sperm from entering the fallopian tubes and fertilizing an egg that may have been ovulated.

Depo-Provera is between 94% and 99% effective. With typical use, three out of every 100 women who use Depo-Provera will become pregnant.

Formulations

There are two versions of Depo-Provera. Each provides the same level of pregnancy protection.

Depo-Provera Injection

The original Depo-Provera formula must be injected into a muscle, either the buttock or upper arm. You must have a shot four times a year (every 13 weeks) to maintain Depo-Provera’s high effectiveness rate. One shot contains 150 milligrams of medroxyprogesterone acetate.

If you get your first Depo shot within the first five days of your period, it will provide immediate pregnancy protection. If you start treatment at any other time in your cycle, you should use a backup method, such as condoms, for at least seven days.

Depo-SubQ Provera 104 Injection

This version contains 31% less hormone than the original Depo shot at 104 milligrams of medroxyprogesterone acetate. Because it has a lower dose of progestin, it may lead to fewer progestin-related side effects.

The subQ stands for subcutaneous, meaning that the shot is injected under the skin, not into a muscle. It requires a smaller needle and is delivered into the thigh or abdomen four times a year (every 12 to 14 weeks).

You can easily switch from Depo-Provera to Depo-subQ Provera 104 at your next scheduled injection. If you do this, you will have immediate pregnancy protection.

Advantages

Compared to other birth control methods, there are a number of reasons why Depo-Provera is appealing to many women.

It's a highly effective and reversible prescription birth control option.
It's a great option if you don't want the hassle of using a daily birth control method like the pill.
You only have to get Depo-Provera injections four times a year. Once you get your Depo shot, you don't need to think about birth control for months.
Depo-Provera may make your periods very light and may stop altogether after a few Depo injections.
Depo-Provera does not interfere with having sex, so it allows for spontaneity.
It's a private and discreet contraceptive choice. Nobody has to know that you use Depo-Provera because there are no wrappers or pill compacts.
Depo does not contain estrogen, so it can be a good alternative if you cannot tolerate estrogen or use combination contraceptives.
Women who are breastfeeding or are six-weeks postpartum can safely use Depo-Provera.

Disadvantages

It's common for birth control to have disadvantages. Depo-Provera is no different, and it's important to know both the pros and the cons before you make a decision. Among the other disadvantages:

Scheduling is important and you must remember to make your injection appointment every 12 weeks. If it's been more than 13 weeks since your last shot (or 14 weeks since your last Depo-subQ 104 shot), make sure to use a backup birth control method because you could be at risk for getting pregnant.
Due to the possibility of bone density loss, it's also recommended that you shouldn't use Depo Provera or Depo-subQ Provera 104 for more than two years.
Many women stop using Depo-Provera during the first year of use due to spotting/irregular bleeding and/or continuous bleeding. This side effect is especially common during the first three months of Depo use.
In a small number of cases, women have experienced skin reactions in the area where they received the Depo shot. The skin around the injection may also get dry, dimpled, or feel lumpy.
You would need to stop your Depo injections one year before you would like to become pregnant. It takes an average of nine to 10 months (and sometimes even a year or longer) to regain fertility and begin ovulating after receiving your last shot.

Some studies show weight gain with Depo-Provera. The manufacturer states that women gain an average of 5.4 pounds the first year and will have gained 8.1 pounds by the end of the second year.
Some women report mild pain associated with the Depo injection.

In 2004, the U.S. Food and Drug Administration (FDA) issued a black box warning advising women that Depo-Provera can cause severe bone density loss. Because of this, Depo-Provera is avoided in adolescent girls.

Unfortunately, there is no way to predict who will get side effects or any way to stop them once they occur. While the symptoms will usually resolve once the treatment is stopped, it may take 12 to 14 weeks to fully return to normal.

Less Common Side Effects

Over the first year of Depo shots, you may notice a few changes as your body adjusts. Additionally, some of the less common side effects include changes in sex drive and appetite as well as hair loss and/or increased hair on the face or body.

In a few women, it may cause depression, nervousness, dizziness, nausea, or headaches. A skin rash or spotty darkening of the skin or sore breasts may also occur.

Additional Considerations

If you're currently using another hormonal method, you can switch to Depo-Provera. You should receive your first Depo shot within seven days after the last day of using your current method—within seven days after taking your last active combination birth control pill, removing your Ortho Evra Patch, or taking out your NuvaRing.

Appropriate Use

Depo-Provera can be a safe birth control option for most healthy women. It's important that you discuss your complete medical history with your doctor before receiving an injection. Depo-Provera is not recommended for adolescent girls or for women who any of the following:

Breast cancer
Thrombophlebitis, a history of thromboembolic disorders, or cerebral vascular disease
Risk factors for osteoporosis: bone disease, excessive alcohol or smoking, a family history of osteoporosis, anorexia, or use of steroid drugs
Significant liver disease
Undiagnosed vaginal bleeding
A desire to become pregnant within the next year

Non-Contraceptive Uses

While Depo-subQ Provera 104 is recognized as a safe and effective form of long-term birth control, it has other indications distinct from original Depo-Provera.

Depo-subQ Provera 104 is also approved for the treatment of endometriosis pain. Research has shown that it's just as effective as leuprolide but with fewer vasomotor symptoms (like hot flashes and sweats) and less bone density loss.

The efficacy of the drug extends to alleviating pelvic pain and tenderness, dysmenorrhea (menstrual cramps), painful intercourse, and the hardening and thickening of endometrial tissue. Both Depo-Provera versions can also help lower your uterine cancer risk.

Cost of Treatment

Under the Affordable Care Act, most insurance plans must cover doctor visits related to birth control and the shot itself is free under most plans. Medicaid may cover the cost as well. Any changes to the Affordable Care Act may affect whether insurance plans cover contraception. Check with your insurance plan to see what your coverage and costs may be.

If you do not have coverage, you will need to pay out-of-pocket for the medical exam. Your cost may be as much as $250 for the first visit and as much as $150 for further visits.

The cost of a Depo-Provera injection can range from $50 to $95. This translates to a total cost of roughly $220 to $650 per year, not including the cost of the office visits.

You may incur additional costs if you are more than two weeks late for your next scheduled shot. Your doctor may require a pregnancy test before your next injection, so you will need to pay for that as well.

A Word From Verywell

Since it was first approved by the FDA, Depo-Provera has been a popular option for birth control. Whether or not it's right for you depends on various factors. Many women have found that a couple of years of regular injections makes managing birth control easier.

Speak with your doctor to see if it's a good fit and be sure to ask any questions you have along the way.