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Generic Name: levonorgestrel intrauterine system (LEE voe nor JES trel IN tra UE ter ine SIS tem)
Brand Name: Mirena

Medically reviewed by Sophia Entringer, PharmD. Last updated on Jan 28, 2021.

What is Mirena?

The Mirena intrauterine device (IUD) contains levonorgestrel, a female hormone that can cause changes in your cervix and uterus. Mirena is a T-shaped plastic intrauterine device that is placed in the uterus where it slowly releases the hormone.

Mirena IUD is used to prevent pregnancy for 6 years. You may use this IUD whether you have children or not. Mirena is aso used for up to 5 years to treat heavy menstrual bleeding in women who choose to use an intrauterine form of birth control.

Levonorgestrel is a progestin hormone and does not contain estrogen. The Mirena IUD releases levonorgestrel in the uterus, but only small amounts of the hormone reach the bloodstream. Mirena should not be used as emergency birth control.


You should not use Mirena if you have abnormal vaginal bleeding, a pelvic infection, certain other problems with your uterus or cervix, or if you have breast or uterine cancer, liver disease or liver tumor, or a weak immune system.

Do not use Mirena during pregnancy. Call your doctor if you think you might be pregnant.

Before taking this medicine

Mirena can increase your risk of developing a serious pelvic infection, which may threaten your life or your future ability to have children. Ask your doctor about your personal risk.

Do not use during pregnancy. Mirena can cause severe infection, miscarriage, premature birth, or death of the mother if left in place during pregnancy. Tell your doctor right away if you become pregnant. If you continue a pregnancy that occurs while using this IUD, watch for signs such as fever, chills, cramps, vaginal bleeding or discharge.

You should not use Mirena if you are allergic to levonorgestrel, silicone, silica, silver, barium, iron oxide, or polyethylene, or if you have:

  • abnormal vaginal bleeding that has not been checked by a doctor;

  • an untreated or uncontrolled pelvic infection (vaginal, cervical, uterine);

  • endometriosis or a serious pelvic infection following a pregnancy or abortion in the past 3 months;

  • pelvic inflammatory disease (PID), unless you had a normal pregnancy after the infection was treated and cleared;

  • uterine fibroid tumors or conditions that affect the shape of the uterus;

  • past or present cancer of the breast, cervix, or uterus;

  • liver disease or liver tumor (benign or malignant);

  • a condition that weakens your immune system, such as AIDS, leukemia, or IV drug abuse; or

  • if you have another intrauterine device (IUD) in place.

To make sure Mirena is safe for you, tell your doctor if you have ever had:

  • high blood pressure, heart problems, a heart valve disorder, a heart attack or stroke;

  • bleeding problems;

  • migraine headaches; or

  • a vaginal infection, pelvic infection, or sexually transmitted disease.

You should not use thw Mirena IUD if you are breastfeeding a baby younger than 6 weeks old. This IUD may be more likely to form a hole or get embedded in the wall of your uterus if you have the device inserted while you are breastfeeding.

How is Mirena used?

The Mirena IUD is inserted through the vagina and placed into the uterus by a doctor. The device is usually inserted within 7 days after the start of a menstrual period.

You may feel pain or dizziness during insertion of the IUD. You may also have minor vaginal bleeding. Tell your doctor if you still have these symptoms longer than 30 minutes.

The Mirena IUD should not interfere with sexual intercourse, wearing tampons, or using other vaginal medications.

Your doctor will need to see you within a few weeks after insertion of the device to make sure it is still in place correctly. You will also need regular annual pelvic exams and Pap smears.

You may have irregular periods during the first 3 to 6 months of use. Your flow may be lighter or heavier, and you may eventually stop having periods after several months. Tell your doctor if you do not have a period for 6 weeks or if you think you might be pregnant.

The Mirena IUD may come out by itself. After each menstrual period, make sure you can still feel the removal strings. Wash your hands with soap and water, and insert your clean fingers into the vagina. You should be able to feel the strings at the opening of your cervix.

Call your doctor at once if you cannot feel the strings, or if you think the IUD has slipped lower or has come out of your uterus, especially if you also have pain or bleeding. Use a non-hormone method of birth control (condom, diaphragm, cervical cap, or contraceptive sponge) to prevent pregnancy until your doctor is able to replace the IUD.

If you need to have an MRI (magnetic resonance imaging), tell your caregivers ahead of time that you have a Mirena IUD in place.

Your device may be removed at any time you decide to stop using birth control. The Mirena IUD must be removed at the end of the 6-year wearing time. Your doctor can insert a new device at that time if you wish to continue using this form of birth control. Only your doctor should remove the IUD. Do not attempt to remove the device yourself.

If you wish to continue preventing pregnancy, you may need to start using another birth control method a week before your Mirena is removed.

Dosing information

Usual Adult Dose for Contraception:

Intrauterine Device (IUD) insertion should be performed by a trained healthcare provider thoroughly familiar with product; product manufacturer labeling should be consulted:

Insert 1 Mirena IUD (52 mg) into uterus

Timing of insertion:
-For women who are not currently using hormonal or intrauterine contraception: Insertion may occur at any time the woman is not pregnant; if inserted after the first 7 days of menstrual cycle, an additional method of contraception should be used for 7 days after insertion
-Switching from an oral, transdermal, or vaginal hormonal contraceptive: Insertion may occur at any time; if inserted during the hormone phase, continue use for 7 days after insertion or until the end of the current treatment cycle
-Switching from an injectable progestin contraceptive: Insertion may occur at any time; if inserted more than 3 months after the last injection, an additional method of contraception should be used for 7 days after insertion
-Switching from a contraceptive implant or another IUD: Insertion should occur on the same day the implant or IUD is removed
-Inserting after abortion or miscarriage:
--First trimester: May insert IUD immediately after a first trimester abortion or miscarriage
--Second trimester: Insertion of IUD should be delayed a minimum of 4 weeks or until the uterus is fully involuted; if involution is delayed, insertion should be delayed until involution is complete; consider the possibility of ovulation and conception occurring prior to insertion and advise patient on need for an additional method of contraception for 7 days after insertion
-After childbirth: Insertion of IUD should be delayed a minimum of 4 weeks after delivery, or until the uterus is fully involuted; if involution is delayed, insertion should be delayed until involution is complete; consider the possibility of ovulation and conception occurring prior to insertion and advise patient on need for an additional method of contraception for 7 days after insertion

Replacement: Mirena should be replaced after 6 years; a new IUD may be inserted for continued use.

-IUD may be removed at any time but must be removed by the end of the prescribed time; if continued use is desired, replace with a new IUD.

What happens if I miss a dose?

Since the Mirena IUD continuously releases a low dose of levonorgestrel, missing a dose does not occur when using this form of levonorgestrel.

What happens if I overdose?

An overdose of levonorgestrel released from the intrauterine system is very unlikely to occur.

What should I avoid while using Mirena?

Avoid having more than one sex partner. The Mirena IUD can increase your risk of developing a serious pelvic infection, which is often caused by sexually transmitted disease. Mirena will not protect you from sexually transmitted diseases, including HIV and AIDS. Using a condom is the only way to help protect yourself from these diseases.

Call your doctor if your sex partner develops HIV or a sexually transmitted disease, or if you have any change in sexual relationships.

Mirena side effects

Get emergency medical help if you have signs of an allergic reaction to Mirena: 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 (a pregnancy that implants in the fallopian tube instead of the uterus). A tubal pregnancy is a medical emergency.

The Mirena 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 Mirena side effects may include:

  • pelvic pain, vaginal itching or infection, missed or irregular menstrual periods, changes in bleeding patterns or flow (especially during the first 3 to 6 months);

  • 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, 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.

What other drugs will affect Mirena?

Some drugs can affect your blood levels of levonorgestrel, which could make this form of birth control less effective. Tell your doctor about all your other medicines, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

In the U.S there are two types of intrauterine device (IUD) available: copper IUDs (such as ParaGard) and hormonal IUDs (such as: Mirena, Liletta, Skyla, and Kyleena). The most common side effects reported with IUDs are pain on IUD insertion, cramps, bleeding, and unwanted pregnancy. Continue reading

No, antibiotics do not affect IUDs such as Kyleena, Mirena, or Skyla. In fact, there are not many contraceptive devices or even contraceptives that are affected by antibiotics, despite popular belief that this is the case. IUDs work directly in the uterine cavity and do not rely on absorption through the stomach, nor metabolism through the liver for their effect and have few interactions. Continue reading

Yes, it is possible to become pregnant with an IUD; however, this is extremely rare, occurring in less than 1% (one out of every 100 women) who use an IUD. If you do become pregnant, there is a higher chance that your pregnancy will be ectopic (occurring outside of the uterus) or you will develop complications with your pregnancy, if it continues. Continue reading

More FAQ

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Mirena only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.