Dosage Details for Mirena

Mirena (levonorgestrel) is a prescription intrauterine device (IUD) used to help prevent pregnancy for up to 8 years.

Mirena is used in adults and certain adolescents to help prevent pregnancy for up to 8 years. It can also help manage heavy menstrual bleeding for up to 5 years.

The active ingredient in Mirena is levonorgestrel.* It’s a kind of hormonal birth control that belongs to a group of drugs called progestins.

Mirena comes in an intrauterine device (IUD). This IUD is a piece of plastic shaped like a “T” that’s placed in the uterus. A healthcare professional inserts the device at a doctor’s office. Mirena releases small amounts of levonorgestrel into your body over time.

This article describes the dosage of Mirena, as well as its strength and how to use it. To learn more about Mirena, see this in-depth article.

* An active ingredient is what makes a drug work.

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This section describes the dosage of Mirena.

Note: The chart below highlights the basics of Mirena’s dosage. Be sure to read on for more detail.

What form does Mirena come in?

Mirena comes in a “T”-shaped plastic IUD. A healthcare professional at a doctor’s office places it in the uterus.

What strength does Mirena come in?

Mirena is available as a 52-milligram (mg) IUD.

What are the usual dosages of Mirena?

The information below describes the dosage that’s available for Mirena.

Dosage for helping to prevent pregnancy

To prevent pregnancy, a healthcare professional inserts a Mirena IUD into your uterus once every 8 years. Once the device is in place, Mirena starts releasing levonorgestrel (the active ingredient*) into your body.

The dose of levonorgestrel that the Mirena IUD releases each day decreases over time. For example, at 24 days after insertion, the IUD releases 21 mcg per day. Then at 1 year after insertion, this decreases to 19 mcg per day.

On average, Mirena releases about:

• 20 mcg per day over the first year
• 15 mcg per day over 5 years
• 13 mcg per day over 8 years

The drug remains effective at helping prevent pregnancy for up to 8 years.

A healthcare professional can remove Mirena at any time. Once they remove it, they can replace it with another Mirena IUD if you’d like.

Your doctor may recommend using an additional form of birth control (such as condoms) for 1 week after Mirena is inserted. This will depend on several factors, such as the timing of your menstrual cycle and whether you were previously using birth control.

Dosage for heavy periods

To manage heavy periods, one Mirena IUD is inserted into your uterus by a healthcare professional once every 5 years. Once the device is in place, Mirena slowly releases levonorgestrel (the active ingredient*) into your body.

With Mirena, the dose of levonorgestrel that the IUD releases each day decreases over time. For example, at 24 days after insertion, the IUD releases 21 mcg per day. Then at 1 year after insertion, this decreases to 19 mcg per day.

On average, Mirena releases about:

• 20 mcg per day over the first year
• 15 mcg per day over 5 years

The drug remains effective to manage heavy menstrual bleeding for up to 5 years.

A healthcare professional can remove Mirena at any time. Once they remove it, they can replace it with another Mirena IUD if you’d like.

* An active ingredient is what makes a drug work.

What’s the dosage of Mirena for adolescents?

Mirena has been studied in people who can become pregnant. It can be used in adolescents under the age of 18 years who have started their periods.

The dosage is the same as for adults. One IUD is inserted for up to 5 or 8 years, depending on what the IUD is being used for.

Is Mirena used long term?

Yes, Mirena is usually used as a long-term treatment or to help prevent pregnancy long term. If you and your doctor determine that it’s safe and effective for you, you’ll likely use it long term.

A healthcare professional inserts Mirena into your uterus. Before insertion, they’ll examine your uterus to confirm Mirena is safe for you to use.

Mirena comes packaged with a sterile insertion device that’s used only once. Your healthcare professional will use it to insert Mirena into your uterus.

For detailed information on how Mirena is inserted, see the manufacturer’s website.

If you have any questions about the insertion process, talk with your doctor.

You can have a healthcare professional remove Mirena whenever you like. Call their office to set up an appointment.

For information on the expiration, storage, and disposal of Mirena, see this article.

Below are answers to some commonly asked questions about Mirena’s dosage.

Is Mirena’s dosage different than the usual birth control pill dosage?

Different forms of birth control contain different active ingredients (the drug that makes them work). Because of this, it’s difficult to accurately compare the strength of one drug with another.

The main difference between Mirena and common birth control pills is that Mirena is an intrauterine device (IUD). You only need to have it inserted at your doctor’s office once every 8 years (for contraception) or once every 5 years for heavy periods. It then releases small amounts of its active ingredient into your body over time. With birth control pills, you have to take a daily oral dose.

For more information on how Mirena is different from birth control pills, talk with your doctor. There are several kinds of birth control and your doctor can help you determine what’s best for you.

How does the dosage for Mirena compare with the dosage for Kyleena?

Mirena is an IUD that contains 52 milligrams (mg) of levonorgestrel. It can be used for up to 8 years to help prevent pregnancy.

Kyleena is an IUD that contains 19.5 mg of levonorgestrel. It can be used for up to 5 years to help prevent pregnancy.

Your doctor can give you more information on both IUDs to help you determine which one is best for you.

The sections above describe the available dosage of Mirena. You may want to talk with your doctor about other intrauterine devices (IUDs) and other available forms of birth control.

Here are some examples of questions you may want to ask your doctor:

• How does the dosage of Mirena compare with other IUDs?
• Will the dosage of Mirena be different if I don’t use it for a full 8 years?
• Why does the amount of levonorgestrel released per day decrease the longer I use Mirena?
• How is Mirena as effective at preventing pregnancy at 5 years as it is at 1, when it’s releasing less of the drug?

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Disclaimer: Austra Health 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.

Last medically reviewed on April 6, 2023