Mirena Side Effects Center

Last updated on RxList: 8/29/2022
Mirena Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Mirena?

Mirena (levonorgestrel-releasing intrauterine device) is a form of birth control that is indicated for intrauterine contraception for up to 5 years and for the treatment of heavy menstrual bleeding in women. Mirena is a hormone-releasing system placed in your uterus (intra-uterine device, or IUD) to prevent pregnancy for up to 5 years.

What Are Side Effects of Mirena?

Common side effects of Mirena are:

  • missed periods (amenorrhea),
  • bleeding and spotting between periods,
  • heavier bleeding during the first few weeks after device insertion,
  • abdominal/pelvic pain,
  • ovarian cysts,
  • back pain,
  • headache/migraine,
  • nervousness,
  • dizziness,
  • nausea,
  • vomiting,
  • bloating,
  • breast tenderness or pain,
  • weight gain,
  • changes in hair growth,
  • acne,
  • depression,
  • changes in mood,
  • loss of interest in sex,
  • itching or skin rash, and
  • puffiness in the face, hands, ankles, or feet.

Mirena may cause serious side effects including:

Get medical help right away, if you have any of the symptoms listed above.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Mirena

Mirena contains 52 mg of levonorgestrel (LNG). Initially, LNG is released at a dose rate of approximately 20 mcg/day. This rate decreases progressively to half that value after 5 years. Mirena must be removed by the end of the fifth year and can be replaced at the time of removal with a new Mirena if continued contraceptive protection is desired.

What Drugs, Substances, or Supplements Interact with Mirena?

Drug interactions and warnings include potential interactions with insulin, warfarin (Coumadin) and steroids. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors.

Mirena During Pregnancy and Breastfeeding

Mirena should not be used during pregnancy. This device can cause severe infection, miscarriage, premature birth, or death of the mother if it is left in place during pregnancy. Tell your doctor right away if you become pregnant while using the Mirena intrauterine system. Small amounts of progestins such as those in Mirena pass into breast milk. If you have recently had a baby and are breastfeeding, wait until your baby is at least 6 weeks old before you start using Mirena.

Additional Information

Our Mirena Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Get emergency medical help if you have severe pain in your lower stomach or side. This could be a sign of a tubal pregnancy.

The IUD may become embedded into the wall of the uterus, or may perforate (form a hole) in the uterus. If this occurs, the device may no longer prevent pregnancy, or it may move outside the uterus and cause scarring, infection, or damage to other organs. Your doctor may need to surgically remove the device.

Call your doctor at once if you have:

  • severe cramps or pelvic pain, pain during sexual intercourse;
  • extreme dizziness or light-headed feeling;
  • severe migraine headache;
  • heavy or ongoing vaginal bleeding, vaginal sores, vaginal discharge that is watery, foul-smelling discharge, or otherwise unusual;
  • pale skin, weakness, easy bruising or bleeding, fever, chills, or other signs of infection;
  • jaundice (yellowing of the skin or eyes); or
  • sudden numbness or weakness (especially on one side of the body), confusion, problems with vision, sensitivity to light.

Common side effects may include:

  • pelvic pain, painful or irregular menstrual periods, changes in bleeding patterns or flow;
  • vaginal swelling, itching or infection;
  • temporary pain, bleeding, or dizziness during insertion of the IUD;
  • ovarian cysts (pelvic pain that disappears within 3 months);
  • stomach pain, nausea, vomiting, bloating;
  • headache, migraine, depression, mood changes;
  • back pain, breast tenderness or pain;
  • weight gain, acne, oily skin, changes in hair growth, loss of interest in sex; or
  • puffiness in your face, hands, ankles, or feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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The following serious or otherwise important adverse reactions are discussed in elsewhere in the labeling:

  • Ectopic Pregnancy [see WARNINGS AND PRECAUTIONS]
  • Intrauterine Pregnancy [see WARNINGS AND PRECAUTIONS]
  • Group A Streptococcal Sepsis (GAS) [see WARNINGS AND PRECAUTIONS]
  • Pelvic Inflammatory Disease [see WARNINGS AND PRECAUTIONS]
  • Perforation [see WARNINGS AND PRECAUTIONS]
  • Ovarian Cysts [see WARNINGS AND PRECAUTIONS]
  • Bleeding Pattern Alterations [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

The data provided in Table 2 reflect the experience with the use of Mirena in the adequate and well-controlled studies as well as in the supportive and uncontrolled studies for contraception and heavy menstrual bleeding (n=5,091). The data cover more than 12,101 women-years of exposure up to 5 years of use, mainly in the contraception studies (11,761 women-years). The frequencies of reported adverse drug reactions represent crude incidences.

The most common adverse reactions (≥10% users) are alterations of menstrual bleeding patterns [including unscheduled uterine bleeding (31.9%), decreased uterine bleeding (23.4%), increased scheduled uterine bleeding (11.9%), and female genital tract bleeding (3.5%)], abdominal/pelvic pain (22.6%), amenorrhea (18.4%), headache/migraine (16.3%), genital discharge (14.9%), and vulvovaginitis (10.5%). Adverse reactions reported in ≥ 5% of users are shown in Table 2.

Table 2: Adverse Reactions ≥ 5% Reported in Clinical Trials with Mirena

System Organ Class Adverse Reactions % (N= 5,091)
Reproductive system and breast disorders alteration of menstrual bleeding pattern, including:
unscheduled uterine bleeding 31.9
decreased uterine bleeding 23.4
increased scheduled uterine bleeding 11.9
female genital tract bleeding 3.5
amenorrhea 18.4
genital discharge 14.9
vulvovaginitis 10.5
breast pain 8.5
benign ovarian cyst and associated complications 7.5
dysmenorrhea 6.4
Gastrointestinal disorders abdominal/pelvic pain 22.6
Nervous system disorders headache/migraine 16.3
Musculoskeletal and connective tissue disorders back pain 7.9
Skin and subcutaneous tissue disorders acne 6.8
Psychiatric disorders depression/depressive mood 6.4

Other adverse reactions occurring in <5% of subjects include alopecia, (partial and complete) device expulsion, hirsutism, nausea, and PID/endometritis.

A separate study with 362 women who have used Mirena for more than 5 years showed a consistent adverse reaction profile in Years 6 through 8 as shown in Table 2. By the end of Year 8 of use, amenorrhea and infrequent bleeding are experienced by 34% and 26% of users, respectively; irregular bleeding occurs in 10%, frequent bleeding in 3%, and prolonged bleeding in 3% of users. In this study, 9% of women reported the adverse event of weight gain; it is unknown if the weight gain was caused by Mirena

Postmarketing Experience

Adverse Reactions From Postmarketing Spontaneous Reports
  • The following adverse reactions have been identified during post approval use of Mirena. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
  • Arterial thrombotic and venous thromboembolic events, including cases of pulmonary embolism, deep vein thrombosis and stroke
  • Device breakage
  • Hypersensitivity (including rash, urticaria and angioedema)
  • Increased blood pressure
Reported Adverse Reactions From Postmarketing Studies

Assessment of Perforation and Expulsion of Intrauterine Devices (APEX IUD) Study

APEX IUD was a large US retrospective cohort study to assess the impact of breastfeeding and timing of postpartum IUD insertion on uterine perforation and IUD expulsion. The analyses included a total of 326,658 insertions, 30% (97,824 insertions) of which were performed in women with a delivery in the previous 12 months. For insertions performed in women who had delivered ≤ 52 weeks before IUD insertion, the majority of postpartum insertions, 57.3% (56,047 insertions) occurred between 6 and 14 weeks postpartum. Breastfeeding data were available in 94,817 insertions performed in women 52 weeks or less after delivery.

The study results indicated that the risk of uterine perforation was highest in women with IUD insertion ≤ 6 weeks postpartum. Immediate postpartum insertion (0-3 days) findings are limited due to the relatively small number of insertions occurring within this time interval. Women who were breastfeeding at the time of insertion were at 33% higher risk of perforation (adjusted hazard ratio [HR]=1.33, 95% confidence interval [CI]: 1.07-1.64) compared to women who were not breastfeeding at the time of insertion. Progressively lower risk of uterine perforation was observed in postpartum time windows beyond 6 weeks, in both breastfeeding and not breastfeeding women. Table 3 presents the uterine perforation rates for LNG IUS stratified by breastfeeding status and postpartum interval.

Table 3: Uterine Perforation1 rates for LNG IUS, by Breastfeeding Status and Postpartum Interval

Postpartum interval at time of insertion Breastfeeding at time of insertion Not breastfeeding at time of insertion
Number of events/ insertions Uterine perforation rate per 1,000 insertions Number of events/ insertions Uterine perforation rate per 1,000 insertions
0 to 3 days 8/1,896 4.22 0/277 0.00
s4 days to ≤ 6 weeks 120/10,735 11.18 28/2,377 11.78
> 6 to ≤ 14 weeks 268/29,677 9.03 80/12,011 6.66
> 14 to ≤ 52 weeks 43/6,139 7.00 22/9,089 2.42
> 52 weeks or no delivery no data available 243/184,733 1.32
1Uterine perforation includes both complete and partial perforation

Risk of expulsion was variable over the postpartum intervals through 52 weeks. Women who were breastfeeding were at 28% lower risk of IUD expulsion (adjusted HR=0.72, 95% CI: 0.64-0.80) compared to women who were not breastfeeding at time of insertion. Table 4 presents the IUD expulsion rates for LNG IUS stratified by breastfeeding status and postpartum interval.

Table 4: Expulsion1 Rates for LNG IUS, by Breastfeeding Status and Postpartum Interval

Postpartum interval at time of insertion Breastfeeding at time of insertion Not breastfeeding at time of insertion
Number of events/ insertions Expulsion rate per 1,000 insertions Number of events/ insertions Expulsion rate per 1,000 insertions
0 to 3 days 187/1,896 98.63 12/277 43.32
4 days to ≤ 6 weeks 185/10,735 17.23 52/2,377 21.88
> 6 to ≤ 14 weeks 421/29,677 14.19 306/12,011 25.48
> 14 to ≤ 52 weeks 120/6,139 19.55 273/9,089 30.04
> 52 weeks or no delivery no data available 5,481/184,733 29.67
1Expulsion includes both complete and partial expulsion


No drug-drug interaction studies have been conducted with Mirena.

Drugs or herbal products that induce or inhibit LNG metabolizing enzymes, including CYP3A4, may decrease or increase, respectively, the serum concentrations of LNG during the use of Mirena. However, the contraceptive effect of Mirena is mediated via the direct release of LNG into the uterine cavity and is unlikely to be affected by drug interactions via enzyme induction or inhibition.

Read the entire FDA prescribing information for Mirena (Levonorgestrel-Releasing Intrauterine System)

© Mirena Patient Information is supplied by Cerner Multum, Inc. and Mirena Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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