In a year of typical use, an estimated 3 out of 100 women using Depo-Provera will get pregnant. But the risk of pregnancy is much lower in women who return every 12 weeks for their injections. Depo-SubQ Provera 104 was highly effective in initial studies. However, it's a newer medication, so current research may not reflect pregnancy rates in typical use.

Among the things to consider about Depo-Provera are:

  • You may have a delay in your return to fertility. After stopping Depo-Provera, it may be 10 months or more before you begin ovulating again. If you want to become pregnant in the next one year or so, Depo-Provera might not be the right birth control method for you.
  • Depo-Provera doesn't protect against sexually transmitted infections. In fact, some studies suggest that hormonal contraceptives such as Depo-Provera may increase a woman's risk of chlamydia and HIV. It isn't known whether this association is due to the hormone or behavioral issues related to the use of reliable contraception. Using condoms will decrease your risk of a sexually transmitted infection. If you're concerned about HIV, talk with your health care provider.
  • There's a potential for loss of bone mineral density. Research has suggested that Depo-Provera and Depo-SubQ Provera 104 may cause a loss of bone mineral density. This loss may be especially concerning in teens who haven't yet reached their peak bone mass. And it's not clear whether or not this loss is completely reversible.

    Because of this, the Food and Drug Administration added strong warnings to the injection packaging cautioning that Depo-Provera and Depo-SubQ Provera 104 shouldn't be used for longer than two years. The warning also states that using these products may increase a woman's risk of osteoporosis and bone fractures later in life. It's a good idea for a woman who has other risk factors for osteoporosis, such as a family history of bone loss and certain eating disorders, to discuss the potential risks and benefits of this form of contraception with her doctor, as well as learn about other contraceptive options.

Other side effects of Depo-Provera may include:

  • Abdominal pain
  • Acne
  • Breast soreness
  • Decreased interest in sex
  • Depression
  • Dizziness
  • Headaches
  • Irregular periods and breakthrough bleeding
  • Nervousness
  • Weakness and fatigue
  • Weight gain

Consult your health care provider as soon as possible if you have:

  • Depression
  • Heavy bleeding or concerns about your patterns of bleeding
  • Trouble breathing
  • Pus, prolonged pain, redness, itching or bleeding at the injection site
  • Severe lower abdominal pain
  • A serious allergic reaction
  • Other symptoms that concern you

Many experts believe progestin-only contraceptive methods, such as Depo-Provera, carry significantly lower risks of these types of complications than do contraceptive methods that contain both estrogen and progestin.

Dec. 13, 2014