Mirena
Mirena birth control is a T-shaped intrauterine device (IUD) from pharmaceutical manufacturer Bayer. The IUD releases levonorgestrel, a hormone that thickens the mucus in the cervix to stop egg fertilization and partially suppresses ovulation.
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What Is Mirena?
Mirena birth control is a T-shaped intrauterine device, or IUD, that releases the hormone levonorgestrel to thicken the mucus within the cervix, preventing the fertilization of eggs. The hormone also thins the lining of the uterus, which can partially suppress ovulation.
The Bayer-manufactured Mirena device is the #1 prescribed IUD in the US. It is made of soft plastic and measures 1.26 inches. A health care professional must place it in (and remove it from) your uterus. You will need to check its thin threads on the bottom yourself once inserted to ensure it is still in place.
Mirena contains a reservoir of levonorgestrel hormone. It lasts up to eight years for pregnancy prevention and eliminates the responsibility of taking a daily pill.
Levonorgestrel vs. Copper IUD
Long-acting, reversible contraception via IUD comes in two options: the hormonal or levonorgestrel IUD and the copper IUD. Both are very effective. It’s important to note that levonorgestrel is a progestogen vs. a progesterone.
The copper IUD has an efficacy rate of 99.2%, so out of every 1,000 people, eight will have an unintended pregnancy. The copper IUD does not contain hormones. It works because the properties of copper affect egg and sperm motility and survival.
A levonorgestrel IUD has a slightly higher efficacy rate of 99.8%, which means only two people out of every 1,000 will have an unintended pregnancy.
How Does Mirena Work?
Mirena birth control releases levonorgestrel, a type of progestin often used in birth control pills. The device slowly releases a continuous low dose of the hormone into your uterus and bloodstream.
Levonorgestrel thins the lining of the uterus and thickens the mucus in the cervix, making it difficult for sperm to move into and survive in the uterus. The thinning of the uterine lining also makes it less likely for an egg to attach to the uterus.
According to Bayer, Mirena is more than 99% effective at preventing pregnancy. The U.S. Food and Drug Administration approved using it for up to eight years.
Mirena Insertion and Removal
Your doctor can insert the Mirena device during a regular doctor’s visit. Mirena insertion takes about five minutes.
You should wait at least six weeks if you have just given birth, had a miscarriage or had an abortion.
You will have to get the Mirena IUD removed after eight years when it is no longer effective, but a doctor or other trained health provider can remove Mirena at any time. If the device moves out of place, your health care provider can insert a new one.
Mirena has no long-term effect on your ability to conceive. Eight out of 10 women who have had their Mirena IUD removed can get pregnant within a year.
Pros and Cons of Mirena IUD
Like any method of birth control, Mirena has pros and cons. On the positive side, it’s highly effective and begins working immediately. However, Mirena cannot work as emergency contraception.
“I will say there are times when Mirena is needed, and it is often a better choice than surgery or full-dose hormonal birth control.”
It’s so tiny you cannot feel it, nor can your partner. Mirena is very low maintenance; you don’t have to remember to do anything for it to function. And it is entirely and almost instantly reversible when you decide to get pregnant.
For some, one con is that a physician, OB-GYN or midwife must insert it. You may experience some cramping immediately after insertion. Additionally, the IUD does not protect against sexually transmitted diseases.
Benefits of Mirena
Mirena is the first and only hormone-releasing IUD that is FDA-approved to treat heavy periods for up to five years in women who choose an IUD for birth control.
Mirena thins the lining of the uterus, which can lessen heavy menstrual bleeding. In one clinical trial, blood loss was reduced more than 50% after six months in nine out of 10 women. It has also been shown to decrease menstrual pain and pain related to endometriosis.
A 2022 clinical study of 80 participants studied the effects of the Mirena IUD on endometrial thickness and curative effect in patients with perimenopausal abnormal uterine bleeding. The endometrial thickness and menstrual volume scores following three months of treatment were remarkably lower than those before treatment and were considerably lower than those of the control group.
- Mirena is more than 99% effective.
- You don’t have to worry about remembering to take a pill.
- It lasts up to eight years, according to the FDA.
- Most insurance plans cover Mirena.
- It is long-term and reversible birth control.
- Women can still breastfeed while using Mirena.
- It uses a lower dose of hormones than some other birth control methods.
- It reduces or stops menstrual flow in women who don’t want a period or suffer from excessive bleeding.
Experts also recommend IUDs such as Mirena as a birth control option for teens and younger adults because they are very effective, need no daily care and last for many years.
Disadvantages of Mirena
As with any birth control method, you should weigh the risks and benefits before using Mirena. One of the disadvantages of Mirena is that it may cause ovarian cysts.
Becoming pregnant while using Mirena can be life-threatening for the mother and baby under certain circumstances.
- It may cause ovarian cysts.
- Pregnancy with Mirena can be life-threatening.
- IUDs can become infected during insertion.
- Device insertion can cause perforation.
- It doesn’t protect against STDs.
- Devise expulsion can occur, leaving the woman at risk of pregnancy.
IUDs may lead to severe infection or pelvic inflammatory disease and perforation of the uterine wall or cervix can occur.
For more information, speak to your doctor about the risks of using Mirena.
Mirena Side Effects
The most common side effects of this birth control include pain, ovarian cysts, menstrual changes and acne.
- Abdominal or pelvic pain
- Acne
- Allergic reactions such as rash, hives, difficulty breathing or facial swelling
- Breast tenderness
- Changes in bleeding, such as spotting or heavier bleeding within the first 3-6 months
- Depression or changes in mood
- Hair loss or unwanted hair growth
- Headache or migraine
- Missed menstrual periods
- Nausea
- Ovarian cysts that typically resolve within 2-3 months
- Pain, bleeding or dizziness during and after placement
- Vaginal discharge
- Vulvovaginitis (genital inflammation)
- Weight gain
Some side effects can be serious. If you experience any signs of an allergic reaction or any of the symptoms listed in the serious side effects section, contact your care provider immediately.
Managing Side Effects of Mirena
Over-the-counter pain medicines like ibuprofen, naproxen or aspirin can usually help with IUD cramps. Additionally, period products such as panty liners or pads may help reduce the incidence of bleeding seeping into your clothes.
If you have cramping or bleeding that doesn’t improve within a few months, talk with your doctor, as they may need to check the placement of your IUD.
Serious Side Effects of Mirena
The more severe side effects that affect Mirena users, such as pregnancy complications, device migration and infection, can be serious and even life-threatening.
- Breast cancer
- Device expulsion, migration or perforation
- Ectopic pregnancy
- Miscarriage
- Pelvic inflammation
- Pseudotumor cerebri (PTC), also called idiopathic intracranial hypertension (IIH)
- Sepsis
There have been several Mirena lawsuits filed against Mirena’s manufacturer for perforation, ectopic pregnancy and PTC, which is increased pressure in the skull.
Ectopic Pregnancy
According to Mirena’s Frequently Asked Questions, roughly one-half of all pregnancies that occur with Mirena are likely to be ectopic. An ectopic pregnancy occurs when a fertilized egg outside of the uterus, typically in the fallopian tubes, begins to develop into a fetus. Without treatment, this condition has a high mortality rate for the pregnant person. However, even with treatment, the fetus is likely to die.
People who have previously experienced an ectopic pregnancy, pelvic infection or tubal surgery have an increased risk of ectopic pregnancy while using Mirena.
Perforation and Migration
Mirena migration is when the IUD shifts to another part of the body or leaves the uterus.
Uterine perforation, which is when the device erodes through your uterus, occurs most often during insertion. However, it may go undetected at first. Perforation risk is higher in those who have recently given birth or are breastfeeding.
Delayed removal of Mirena in cases of perforation may result in the device migrating outside of the uterine cavity.
Expulsion
Complete or partial expulsion of Mirena may occur, rendering it ineffective as a contraceptive. Expulsion may cause symptoms of bleeding or pain, but it may also be asymptomatic and go unnoticed.
The cause of expulsion is usually unknown, but people who have never been pregnant or have heavy periods are more likely to experience this side effect.
Sepsis
Sepsis, which is a severe infection, can cause organ damage if left untreated. The Sepsis Alliance guidelines of T.I.M.E. provide guidance on how to detect sepsis. High temperature, symptoms of infection, altered mental state, and extreme illness are potential symptoms of sepsis. Contact your care provider immediately if you experience any symptoms.
Spontaneous Abortion of Intrauterine Pregnancy
Patients who have become pregnant with an IUD in place may experience a septic abortion where septicemia, septic shock and death may occur.
If you become pregnant, contact your provider right away to have Mirena removed promptly. Leaving Mirena in place may increase the risk of spontaneous abortion and preterm labor.
It is essential not to remove Mirena on your own. Aside from the risk of the device getting stuck, probing the uterus by shifting the device and removing Mirena incorrectly may also result in spontaneous abortion. Only allow a professional to remove your device.
Pelvic Infection
Pelvic or lower abdominal pain, foul-smelling vaginal discharge, bleeding, fever and genital sores or lesions are potential signs of infection. Your doctor will likely remove Mirena if the pelvic infection is severe or does not respond to treatment.
Pelvic Inflammatory Disease (PID)
There is an increased risk of PID in IUD users, most likely due to organisms being introduced to the uterus during insertion. In clinical trials, 3.5% of Mirena users reported upper genital infections, which occurred more frequently in the first year.
Pseudotumor Cerebri (PTC)
Intracranial hypertension is also known as a “false brain tumor.”
Hormonal IUDs like Mirena put users at an increased risk for pseudotumor cerebri, meaning false brain tumor. The condition is also called idiopathic intracranial hypertension. PTC occurs when there is increased pressure between the skull and brain that isn’t caused by a mass or lesion. This high pressure in the skull can be due to the buildup or poor absorption of cerebrospinal fluid. PTC can cause vision loss from swelling within the eyes, debilitating headaches and reduced quality of life.
“The risk seems highest during the first few months of use but can happen at any time. Early diagnosis is important to prevent vision loss,” Sylejmani said.
You should report symptoms like headaches, vision issues and ringing in the ears to your doctor immediately.
Mirena FDA Warnings
The most recent FDA warnings about Mirena are in Mirena’s 2008 labeling updates. These warnings cover several of its severe side effects.
- Intrauterine pregnancy
- If a non-ectopic pregnancy occurs with a Mirena IUD in place, there are still several risks, including sepsis, miscarriage and premature labor.
- Irregular bleeding or amenorrhea
- Mirena IUDs can affect regular bleeding patterns, resulting in irregular bleeding, spotting, amenorrhea and similar concerns.
- Embedment
- Mirena IUDs may become embedded in the uterine wall, decreasing its contraceptive effects. Sometimes, embedded IUDs will need to be surgically removed.
- Ovarian cysts
- Mirena IUDs may increase the risk of ovarian cysts in some patients. Usually, they will disappear on their own within a few months.
- Risks of mortality
- While IUDs are a safe form of birth control overall, they still have a small risk of mortality. It is important to fully understand this risk before selecting a type of birth control to use.
Patients must consider these potential risks and their own medical history to evaluate whether the Mirena IUD is the best option for them.
Who Should Not Use Mirena?
Women who are pregnant or suspect they might be pregnant should not use Mirena. There are several gynecological conditions that make the use of Mirena ill-advised or dangerous. These include uterine abnormalities such as fibroids, a history of pelvic inflammatory disease, postpartum endometriosis, a recent infected abortion, abnormal pap smears, or genital bleeding or infections.
Individuals with a history of liver disease or tumors, or breast cancer, should avoid using Mirena.
If you have known hypersensitivities to the IUD or any of its components, avoid Mirena and consider other birth control options.
Mirena Interactions
When you take two or more medicines at the same time, the effects of one medicine can counteract the other, which is known as an interaction. It’s important, therefore, to tell your doctor what medications you are taking.
Certain drugs and herbal supplements can make Mirena less effective. Examples of these substances include some blood thinners, anti-anxiety drugs and anti-seizure medications. Anti-retroviral drugs, antibiotics and St. John’s wort may also interact with Mirena.
How Much Does Mirena Cost?
Mirena can cost anywhere from $0 to $1,300. Under the Affordable Care Act, plans in the health insurance marketplace must cover some type of contraception.
Bayer has indicated that its surveys show 95% of women were covered for an IUD like Mirena, with little to no out-of-pocket costs.
If you do not have insurance, the cost of Mirena is $1,049.24, or $12.49 per month over a 7-year period.
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