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Mirena Side Effects

Though Mirena is considered highly effective at preventing pregnancy, thousands of women have experienced severe Mirena side effects.

Mirena Side EffectsMirena is one brand of a hormonal intrauterine device (IUD) used for long-term birth control.  It is a flexible, plastic T-shaped device that contains a synthetic progesterone, levonorgestrel.

Mirena Side Effects

Mirena was approved by the FDA in 2000 to prevent pregnancy in women who have already had one or more children.  It was later approved as a treatment for heavy menstrual bleeding and its use was expanded to include women who have not had children.

Mirena is constructed of a T-shaped, flexible plastic which is impregnated with a progestin, levonorgestrel.  After insertion into the uterus, the Mirena IUD releases the hormone, levonorgestrel slowly, over a period of five years.  After five years, the device must be removed and replaced.

Mirena works to prevent pregnancy in three ways:

  • Inhibits egg production from the ovaries
  • Thickens cervical mucus to prevent sperm from entering the uterus
  • Thins the uterine lining making it difficult for an egg to implant

Mirena is considered to be more than 99% effective, much higher than other forms of birth control.  It has been used by millions of women in the U.S. and around the world, but thousands of women have developed severe side effects from the Mirena IUD.   Many of these women who were injured by Mirena have filed lawsuits against the manufacturer, Bayer.

Mirena was Bayer’s first hormonal IUD but has since introduced two additional products, Kyleena, and Skyla which contain lower levels of the same hormone, levonorgestrel.  The company faces thousands of lawsuits for side effects caused by Mirena but has also faced complaints about their other hormonal birth control products.

Read more about IUDs

Mirena Irregular Bleeding

One of the most common side effects caused by Mirena is irregular bleeding.  Though irregular bleeding is expected during the first three to six months, bleeding complications may be more severe.  The Food and Drug Administration (FDA) has received more than 45,000 adverse event reports regarding bleeding episodes which occurred in women who used Mirena.

Due to the continuous release of levonorgestrel from the device, in the first several months of Mirena use, women may expect:

  • Spotting
  • Irregular bleeding
  • Heavy menstrual bleeding
  • Continuous bleeding
  • Frequent menstrual period
  • Infrequent menstrual period (oligomenorrhea)
  • The absence of menstrual period (amenorrhea)

Many women see a lessening of menstrual bleeding over time as their bodies become used to the hormone, but others have experienced or continue to experience heavy bleeding which may be life-threatening.  Chronic bleeding may result in anemia or when severe, may become a medical emergency.  Bleeding that is unusually heavy or does not go away should be reported to healthcare professional.

In some cases, complications caused by the device itself, rather than the hormone, may contribute to sudden bleeding.  Sudden bleeding or bleeding which becomes worse may be caused by complications such as device migration, endometrial changes, infection, or other physical problems and should be reported to a healthcare professional immediately, especially if accompanied by pain, swelling or fever.

Certain medications may increase the risk of unusual or heavy bleeding with Mirena.  Taking blood thinners or other medications like Aspirin may decrease the blood’s ability to clot and may lead to an uncontrolled episode of bleeding or hemorrhage.  It is important for those considering Mirena to tell their doctor about all of the medication they are taking.

Lack of bleeding (amenorrhea) or infrequent menstrual period (oligomenorrhea) may occur in about 20% of Mirena users.  Within the first year, women who do not have a menstrual period may require close monitoring to ensure that pregnancy has not occurred.

Other Common Side Effects of Mirena

Weight gain is a concern of many women using long-term hormonal birth control.  Evidence shows that the average weight gain from Mirena use was about 4.4 pounds in the first 6 to 12 months.  Other reports show that only about 5% of women considered weight gain to be a significant problem.

Most of the common side effects are similar to those of birth control pills.  They are also similar to other hormonal IUDs including Kyleena, Skyla and Liletta and include:

  • Pelvic or abdominal pain
  • Acne
  • Breast tenderness
  • Mood changes
  • Nausea
  • Vaginal discharge
  • Allergic reaction

Severe Mirena Side Effects and Complications

Mirena is considered highly effective and safe for most women.   Some users, however, have reported severe side effects which may become serious or indicate a medical complication.

Device Migration and Perforation

The Mirena IUD is intended to be inserted through the vagina and cervix into the uterus where it remains in place.  It is possible, however, for the device to migrate from its position.  Device migration may increase the risk of pregnancy and may also perforate the uterus.  If this occurs, the device may migrate to other areas of the body including the pelvic or abdominal cavity, bladder, or intestines and may damage blood vessels.

Implantation of Mirena immediately after childbirth may increase the risk of uterine perforation.  Device implantation should not occur for the first six weeks after childbirth or late-term miscarriage or abortion and some experts recommend waiting up to six months after delivery.

Device migration with or without organ perforation can result in serious complications including pain, abscess, adhesions, infections, and damage to nearby organs.  “Devices which have migrated will require surgical removal and, in some cases, may require more than one surgery to locate and extract the device.

Device Expulsion

Though Mirena is intended to be left in place in the uterus for the five-year lifespan of the device, some women experience device expulsion.  About 6% of Mirena users have spontaneous expulsion with few other complications.  Device expulsion will cease the contraceptive action of the IUD and increase the risk of pregnancy.  Women who have not given birth are more likely to have device expulsion.

Pseudotumor Cerebri

Mirena IUD has been linked to a rare but serious condition known as pseudotumor cerebri (PTC), also called idiopathic intracranial hypertension.  PTC has symptoms that appear to be similar to a brain tumor but are caused by an increase of pressure in the skull.  Symptoms include:

  • Double vision
  • Spotted or blurry vision
  • Vision loss
  • A severe headache
  • Tinnitus or ringing of the ears
  • Papilledema (swelling of the optic disk)
  • Eye pain

PTC is rare but has been linked to levonorgestrel implants.  Visual disturbance, severe headache or symptoms of PTC should be reported to a health professional immediately.

Pregnancy Complications

Though Mirena is considered to be more than 99% effective at preventing pregnancy, unintended pregnancy has occurred in Mirena users.  Over half of the pregnancies that occur while using Mirena are an ectopic pregnancy or tubal pregnancy.  These will require surgical intervention to remove the fertilized egg from the fallopian tube.

Women who become pregnant while using Mirena are also at increased risk for premature delivery, miscarriage, and sepsis.  In most cases, a surgical removal of the fertilized egg will be recommended to prevent a septic abortion, a life-threatening condition.

Pelvic Inflammatory Disease (PID)

Mirena has been shown to increase the risk of a serious pelvic infection known as pelvic inflammatory disease.  PID may be caused by any bacterial infection that affects the reproductive system in females.  An existing vaginal infection or other infection in the reproductive system will increase the risk of developing PID.

PID has occurred within 3 weeks of implantation in less than 1% of Mirena users and is more common in those with a history of PID or certain vaginal infections.  Women with a history of PID should not get Mirena IUD.

Mirena IUD FDA Warnings

Mirena IUD was approved in 2000 for prevention of pregnancy in women who have had at least one child, however, marketing materials produced by Bayer, implied that the device was suitable for all women and failed to emphasize limitations.  Marketing materials implied the device increased “simplicity” and added to “intimacy” in relationships, without stating clear risks.  Marketing representatives were reported to have said that the device was maintenance free and would even help “improve appearance”.

Claims of improved relations were shown to be false in product information showing decreased libido, abdominal pain, and other side effects.  Improved appearance was shown to be false by the increased occurrence of acne and the device does not allow the user to avoid regular monitoring, therefore it does not free the user from maintenance routines.  In 2008, the FDA issued a warning about Mirena and required that Bayer discontinue false marketing and update prescribing information.

Because of the false claims of Bayer and failure to warn the public and medical profession, many women or their doctors may not have had adequate warnings.  Thousands of serious adverse event reports have been received by the FDA and many of these women have filed lawsuits against Bayer for side effects and injuries caused by Mirena.

Notwithstanding claims relating to this product, the drug/medical device remains approved by the U.S. FDA.

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