Mirena (levonorgestrel) is a brand-name intrauterine device (IUD) that’s prescribed to help prevent pregnancy and treat heavy menstrual bleeding. As with other drugs, Mirena can cause side effects, such as headache and pelvic pain.

Mirena belongs to a drug class called progestins. The medication is not available in a generic version.

Read on to learn about potential common, mild, and serious side effects of Mirena. For a general overview of the drug, including details about its uses, see this article.

Mirena can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Mirena in clinical trials:

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Mirena use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Mirena’s prescribing information.

Mild side effects that have been reported with Mirena include:

  • pain or dizziness after placement of Mirena
  • back pain
  • abdominal or pelvic pain
  • breast pain
  • nausea
  • vaginal discharge
  • vulvovaginitis
  • hair loss
  • increased growth of body hair
  • changes in menstrual periods, such as lighter bleeding or spotting between periods*
  • headache*
  • acne*
  • mild allergic reaction*

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Mirena and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Mirena may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Mirena’s prescribing information.

If you develop serious side effects while taking Mirena, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • Perforation (Mirena embeds in or pierces the wall of your uterus). If this happens, Mirena won’t prevent pregnancy. Symptoms can include:
    • severe pain or bleeding when Mirena is inserted
    • pain or bleeding that gets worse after Mirena is inserted
    • being unable to feel the threads of Mirena after insertion
  • Expulsion (Mirena comes out of your uterus). It won’t protect you from pregnancy if this happens. Symptoms can include:
    • pain or bleeding when Mirena is inserted
    • being unable to feel the threads of Mirena after insertion
  • Severe infection after Mirena is inserted. Symptoms can include:
    • severe pain
    • fever and chills
    • nausea and vomiting
  • Growth of benign (noncancerous) ovarian cysts. Symptoms can include:
    • pain during sex
    • pelvic pain
  • Pelvic inflammatory disease (PID).*
  • Changes in mood, including depression*
  • Severe allergic reaction.†

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after using Mirena. However, this side effect wasn’t reported in clinical trials. To learn more, see the “Side effect specifics” section below.

Mirena may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Will Mirena cause certain side effects after 5 years?

No, Mirena won’t cause different side effects after 5 years compared to usual side effects the drug can cause. Mirena can be used to help prevent pregnancy for up to 8 years. It can also be used to manage heavy menstrual bleeding for up to 5 years.

Mirena’s side effects may increase, decrease, or stay the same depending on how your body responds to the drug.

If you have concerns about using Mirena for longer than 5 years, talk with your doctor or pharmacist.

Is weight gain a possible side effect of Mirena?

It’s not likely. Weight gain was not a reported side effect in Mirena’s clinical trials.

However, in a separate study, females* who used Mirena for up to 8 years reported weight gain as a side effect. It’s unknown if the weight gain was caused by Mirena or something else. If you have concerns about weight changes while using Mirena, talk with your doctor or pharmacist.

* Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.

Learn more about some of the side effects that Mirena may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Mirena.

Changes in menstrual bleeding

Mirena can cause changes in menstrual bleeding. In clinical trials, this was a common side effect. Symptoms can include:

  • bleeding that happens between periods (spotting)
  • menstrual bleeding that is heavier or lighter than usual
  • amenorrhea (periods that stop altogether)
  • increased cramping during periods

What you can do

For the first 3 to 6 months after Mirena is placed, you may have spotting or periods that are heavier than usual. Over time, the bleeding should get lighter. However, let your doctor know if you:

  • have menstrual bleeding that continues to be heavy after 3 to 6 months
  • have menstrual bleeding that gets lighter for a few months and then is suddenly heavy again
  • do not have a period for 6 weeks while Mirena is in place (your doctor may recommend a pregnancy test)

Neurological side effects, such as headache or migraine

In Mirena’s clinical trials, headache and migraine were commonly reported side effects. Symptoms can include pain in the face, head, or neck. This pain is typically constant, throbbing, dull, or sharp.

What you can do

Talk with your doctor if you have headaches that are worse than usual or concerning to you. They may recommend medications to treat your headaches, such as acetaminophen (Tylenol) or ibuprofen (Advil). You can also try:

  • ice packs or heat packs
  • gentle massage
  • light exercise, such as walking
  • resting in a quiet, dark room

Changes in mood, such as depression

Depression was reported in Mirena’s clinical trials. This side effect was not common. Symptoms of depression can include:

  • feeling sad or hopeless
  • feeling angry or irritable
  • losing interest in normal activities
  • feeling very tired or fatigued
  • having problems falling asleep or staying asleep
  • memory problems or problems concentrating
  • thinking about hurting yourself

What you can do

Talk with your doctor if you have symptoms of depression that are new or getting worse. They may recommend treatment for your depression. Or in some cases your doctor may recommend a different form of birth control.

Acne

In clinical trials of Mirena, acne was a side effect that was not commonly reported. Acne may occur on the face, chest, or back. Symptoms can include:

  • papules (small red bumps)
  • blackheads
  • whiteheads
  • pustules (small bumps full of pus)
  • skin discoloration and scarring

What you can do

If you develop acne that is bothersome, talk with your doctor. They may recommend different treatment options. There are topical medications available without a prescription. Examples include:

  • benzoyl peroxide
  • salicylic acid
  • adapalene
  • glycolic acid and lactic acid
  • azelaic acid

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) was a side effect that was rarely reported in clinical trials of Mirena. Symptoms can include:

  • pelvic pain or pain in the lower abdomen
  • vaginal discharge with a foul odor
  • chills or fever
  • unexplained heavy bleeding (bleeding that’s not due to your period)
  • sores on the genital area
  • painful sex

What you can do

Talk with your doctor right away if you have any of the symptoms listed above. If left untreated, PID can cause serious complications, such as infertility.

Allergic reaction

As with most drugs, Mirena can cause an allergic reaction in some people. However, this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep using Mirena. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you have Mirena inserted. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions. The conditions and factors to consider include:

Genital or pelvic infections. Mirena can increase your risk of pelvic infections. Your doctor may not recommend Mirena for you if you:

  • have pelvic inflammatory disease (PID)
  • had PID in the past and have not had a normal pregnancy after the infection was past
  • had a severe pelvic infection in the past 3 months after being pregnant
  • have multiple sexual partners or if your partner has multiple partners
  • misuse IV drugs
  • have problems with your immune system, such as lupus or AIDS

Uterus shape that is unusual. If your uterus has an unusual shape, or if you have uterine fibroids, Mirena may not work as well for you. These conditions may cause more side effects of Mirena. Your doctor may recommend a different birth control option for you.

Migraine. If you have migraine headaches, let your doctor know before having Mirena inserted. Mirena may worsen migraine episodes. Ask your doctor what other birth control options they recommend.

Uterine or cervical cancer. If you have cancer of the uterus or cervix, your doctor typically won’t prescribe Mirena. Instead, they’ll likely recommend a different form of birth control for you.

Liver cancer or liver disease. Some drugs that prevent pregnancy, such as Mirena, can worsen liver problems. Tell your doctor about any liver cancer or other liver problems, such as cirrhosis, you may have. They’ll likely recommend a different form of birth control for you.

Breast cancer or other progestin-sensitive cancer. Mirena contains the drug levonorgestrel, which is a type of progestin. This drug can worsen certain types of cancer, including breast cancer. Tell your doctor if you’ve ever been diagnosed with cancer. They’ll recommend a different birth control option.

Undiagnosed uterine bleeding. If you have bleeding from your uterus with no known cause, your doctor typically won’t prescribe Mirena. Ask your doctor what birth control options are safer for you.

High blood pressure. Mirena can increase your blood pressure. If you already have high blood pressure, having Mirena inserted may make it worse. Your doctor can recommend if Mirena is safe for you.

Stroke, past heart attack, or blood clots. Mirena may cause blood clots. If you’ve had a stroke, heart attack, or blood clots in the past, having Mirena inserted may increase your risk for these conditions. Also, be sure and tell your doctor if you take medication to prevent blood clots, such as aspirin. Ask your doctor what birth control options are best for you.

Allergic reaction. If you’ve had an allergic reaction to Mirena or any of its ingredients, your doctor will likely not prescribe Mirena. Ask your doctor what other medications may be better options for you.

Alcohol with Mirena

There’s no known interaction between Mirena and alcohol. If you have concerns about drinking alcohol with Mirena, talk with your doctor.

Pregnancy and breastfeeding while taking Mirena

Mirena should not be used during pregnancy. If you become pregnant while Mirena is in place, you have an increased risk for:

Tell your doctor right away if you think you may be pregnant while Mirena is inserted. They’ll likely recommend that you have Mirena removed.

It’s not known to cause harm to a child who is breastfed. Mirena passes into breast milk in small amounts. Mirena may decrease the amount of breast milk that someone produces. If you have concerns about safe ways to feed your child while Mirena is inserted, talk with your doctor.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Like other medications, Mirena may cause side effects. Most are mild and may improve over time. If you’d like to learn more about Mirena, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information about Mirena. For details about other aspects of Mirena, refer to this article.
  • A look at pregnancy prevention. For details about pregnancy prevention, see our sexual health hub.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.