1. Health
Send to a Friend via Email

Mirena Intrauterine Device

The Levonorgestrel IUD


Updated April 10, 2014

Mirena Intrauterine Device

Mirena IUD

Photo © 2007 Dawn Stacey


The Mirena intrauterine device (IUD) is a small, "T-shaped" contraceptive device made of flexible plastic and must be inserted by a qualified health-care professional (such as an ob/gyn or nurse practitioner). Mirena releases a low amount of progestin levonorgestrel continuously over a 5-year period as a way to prevent pregnancy.


How It Works:

The Mirena IUD helps prevent sperm from joining with an egg by affecting how the sperm move. Basically, it interferes with the movement of the sperm toward the egg. The hormonal component in Mirena makes it more effective than the ParaGard IUD. Mirena is effective immediately if inserted within 7 days after the start of your period. If you have Mirena inserted at any other time during your menstrual cycle, use another method of birth control during the first week after insertion. Pregnancy protection will begin after 7 days.



  • It can provide continuous pregnancy prevention for 5 years and can be removed anytime within that 5-year period

  • Convenient and hassle-free – once inserted, you don’t have to do anything

  • According to Planned Parenthood, IUDs are the most popular form of reversible birth control in the world

  • An IUD is the most inexpensive long-term reversible method of contraception

  • Mirena can help protect against pelvic inflammatory disease (PID) because it thickens cervical mucus and decreases menstrual flow

  • IUDs can improve a woman's sex life by allowing for spontaneity

  • A good alternative option for women who cannot tolerate estrogen-based contraceptive

  • After removing the IUD, a woman’s ability to become pregnant returns quickly

  • It is an extremely private and discreet birth control method. Nobody can tell if you are using it, and there is no packaging or other evidence of use that may embarrass some women

  • The Mirena IUD can reduce menstrual cramps and the amount of bleeding that accompanies a woman’s period. Typically, women using Mirena may see that their menstrual flow is reduced by 90 percent. In approximately 20 percent of Mirena users, their flow stops altogether within one year. This could lower one’s risk for anemia.

  • For women who choose Mirena for contraception, it is the only FDA-approved contraceptive to treat heavy menstrual bleeding.


Although most women do not experience any trouble adjusting to an IUD, some women may have heavy bleeding and cramping during the first few weeks or months after insertion. However, doctors can prescribe medication that can lessen cramps and bleeding during menstruation.

It is not unusual for some spotting to occur between periods during the first few months of IUD use.

Some women may endure cramping or backache for several days or weeks after the IUD is inserted.

For some women, the unpredictable bleeding between periods does not stop after the first few months. The most common reason that women request Mirena removal is because of this irregular bleeding profile.


Side Effects:

Women may experience side effects, but in most cases, they will go away after the first few weeks to months. These include:
  • Changes to menstrual flow and spotting between first few periods
  • Lower abdominal pain and/or back pain
  • Nausea
  • Acne
  • Headaches
  • Mood changes
  • Breast tenderness
  • Ovarian cysts have been diagnosed in about 12 percent of Mirena users. In most cases, they disappeared spontaneously during 2 to 3 months of observation


Possible Complications:

Serious problems with Mirena are rare. It is critical to report any problems to your doctor right away to avoid further complications.
  • Perforation: An IUD can, rarely, be pushed through the uterus wall during insertion. Generally, this is discovered and corrected right away. If not, the IUD can move into other parts of the pelvic area and may damage internal organs. Surgery may then be needed to remove the IUD.
  • Infection: Although there is some risk of PID associated with IUD use, the risk is small after the first 20 days following insertion. Generally PID is sexually transmitted. You have a higher risk of getting PID if you or your partner have sex with multiple partners. Pelvic infection can be caused by bacteria getting into the uterus during insertion. Most infection develops within 3 weeks of insertion. Infection (due to the IUD insertion) after 3 weeks is rare. Infection that occurs after this time is most likely due to exposure to STD's during sexual intercourse. Studies indicate that IUDs don't cause PID or infertility.
  • Expulsion: Mirena could partially or completely slip out of the uterus. This is more likely to happen in women who have never had a baby, younger women and during the first few months of use (although it can also happen later on). If this occurs, you can become pregnant, so use a back-up birth control, such as a condom, and call your doctor. Mirena must be removed if it becomes partially expelled. It is a wise idea to check your pads and tampons during your period to make sure that the IUD has not fallen out.




Who Should Use Mirena:

According to Bayer HealthCare Pharmaceuticals, the manufacturer of Mirena, this IUD is appropriate for women who have had at least 1 child, who are in a stable, mutually monogamous relationship, and have no risk or history of ectopic pregnancy or pelvic inflammatory disease.


It should be noted, however, that the manufacturer also says that this is because most of the research on Mirena for FDA approval was conducted on women who had at least one child. The American College of Obstetricians and Gynecologists (ACOG) recommends that both women who have not given birth as well as teenagers could benefit from IUD use (either Mirena or ParaGard). And, despite the manufacturer’s guidelines, many doctors have been inserting Mirena in these populations for years.

Mirena is not recommended for women who:

  • Have ever had PID
  • Currently have an untreated pelvic infection
  • May be pregnant
  • Have or may have a STD
  • Have/had breast cancer
  • Have had a pelvic infection in the past three months following either childbirth or an abortion
  • Might have cancer of the cervix or uterus
  • Are already using an IUD
  • Have an abnormally shaped uterus
  • Have liver disease or a liver tumor
  • Have unexplained bleeding from the uterus
  • Have more than one sexual partner, or a sexual partner who has more than one sexual partner
  • Have had, or are at risk of having, an ectopic pregnancy
  • Are allergic to levonorgestrel, silicone or polyethylene
  • Have a condition that changes the shape of the uterus (such as large fibroid or tumor)
  • Get infections easily, including women with immune-system problems, leukemia, AIDS, or who abuse intravenous drugs



Next Page: More on the Mirena IUD: Increased Risk Factors, How To Obtain, Checking Your IUD, Removal, Costs, Effectiveness, and STD Protection

Related Video
Maximize Morning Quality Time

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.