Mirena Side Effects & Sciatica

Mirena is a soft, flexible plastic intrauterine device, or IUD, placed into the uterine cavity by a physician. It is used to prevent pregnancy or in women who have heavy periods.

The device must be placed within seven days of onset of the menstrual period and may be left in place up to, but no longer than, five years.

Mirena releases 20 mcg of levonorgestrel every day during the five-year usage period. This IUD is effective but may be associated with several side effects.


Mirena may cause headaches or migraines in about 8 percent of patients, reports the “Drug Information Handbook.” Patients may choose to take acetaminophen to alleviate headaches or migraines until the body adjusts to the medication. If the patient continues to experience this side effect, she should speak with a physician.

Cramps and Vaginal Bleeding

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Immediate Side Effects After Having a Mirena Inserted

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Up to 52 percent of women may experience uterine cramps and vaginal bleeding may occur right after the insertion of Mirena. Pelvic pain may also occur in about 13 percent of women. The patient may ask the physician about medications to prevent pain or cramps. If symptoms continue for more than 30 minutes, the patient should contact a health care provider, states Mirena-US.com.

Changes in Menstrual Cycle

Mirena-US.com explains that women may experience irregular menstrual cycles for the first three to six months. Up to 23 percent of women may experience bleeding or spotting, according to RxList.com. Most women will notice a decrease in the amount of bleeding days.

About 24 percent of women may cease to have a menstrual period, also known as amenorrhea; this usually occurs within the first year.

Once Mirena is removed, the patient’s menstrual period will come back. If the patient does not have a menstrual period and experiences symptoms of pregnancy, she should contact a health care provider to make sure she is not pregnant.

Altered Mood

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5 Possible Causes of Pelvic Pressure in Women

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Mirena may cause depressed or altered mood in 6 percent of women, according to the “Drug Information Handbook.” This is due to the changes in hormone levels the drug is producing. Mood tends to improve as the body gets accustomed to the new drug.

Uterine Perforation

Uterine perforation is extremely rare with the use of Mirena, but it is a serious side effect. Women who have just given birth, are breast-feeding or have an abnormally-shaped uterus are at increased risk.

Patients should keep all doctor appointments and be aware of the signs and symptoms of complication, which include severe lower abdominal pain that may or may not occur with bleeding. The IUD has threads as the end that should be checked periodically by the patient to ensure it is still in the proper place.


Sciatica is pain, weakness or numbness in the leg and may appear in some women on Mirena. Drugs.com warns that if a patient feels sudden pain in a leg or numbness in an arm or leg, she should seek medical attention right away.