Myfembree Side Effects

Generic name: estradiol / norethindrone / relugolix

Medically reviewed by Philip Thornton, DipPharm. Last updated on Feb 8, 2025.

Note: This document provides detailed information about Myfembree Side Effects associated with estradiol / norethindrone / relugolix. Some dosage forms listed on this page may not apply specifically to the brand name Myfembree.

Applies to estradiol / norethindrone / relugolix: oral tablet.

Serious side effects of Myfembree

Along with its needed effects, estradiol / norethindrone / relugolix may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking estradiol / norethindrone / relugolix:

Other side effects of Myfembree

Some side effects of estradiol / norethindrone / relugolix may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

This medicine may increase your risk of early pregnancy loss. Your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (eg, condoms, spermicide) during treatment and for at least 1 week after the last dose. If a pregnancy occurs while using the medicine, tell your doctor right away.

Do not use this medicine if you smoke cigarettes or if you are over 35 years old. If you smoke while using this medicine, you increase your risk of having a heart attack, stroke, or blood clot. Your risk is even higher if you are over age 35, if you have diabetes, high blood pressure, high cholesterol, or if you are overweight. Talk with your doctor about ways to stop smoking. Keep your diabetes under control. Ask your doctor about diet and exercise to control your weight and blood cholesterol level.

Check with your doctor right away if you have pain in the chest, groin, or legs, especially the calves, difficulty with breathing, a sudden, severe headache, slurred speech, a sudden, a sudden loss of coordination, or vision changes while using this medicine.

This medicine can cause your bone mineral density to decrease, which may lead to osteoporosis or weakened bones. Check with your doctor if you have pain in the back, ribs, arms, or legs, or a decrease in your height.

This medicine may increase your risk of having hormone-sensitive cancer, including breast cancer. Check with your doctor right away if you have clear or bloody discharge from the nipple, an inverted nipple, dimpling of the breast skin, a lump in the breast or under the arm, crusting or scaling of the nipple, redness or swelling of the breast, or a sore on the skin of the breast that does not heal.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. Also tell your doctor if you have sudden or strong feelings, including feeling nervous, angry, restless, violent, or scared. If you or your caregiver notice any of these side effects, tell your doctor right away.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea or vomiting, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver or gallbladder problem.

This medicine may cause changes in menstrual bleeding, which may decrease your ability to recognize pregnancy. Talk to your doctor if you have concerns.

This medicine may cause thinning or loss of hair. Talk with your doctor if you have any concerns about this.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine for at least 4 to 6 weeks before having surgery.

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

For healthcare professionals

Applies to estradiol / norethindrone / relugolix: oral tablet.

General adverse events

In women with heavy menstrual bleeding associated with uterine fibroids, the most common adverse reactions occurring in 3% of patients or greater included vasomotor symptoms, uterine bleeding, alopecia, and decreased libido. Serious adverse reactions occurring in up to 3% of patients included uterine myoma expulsion and menorrhagia, uterine leiomyoma (prolapse), cholecystitis, and pelvic pain.

In women with moderate to severe pain associated with endometriosis, the most common adverse reactions occurring in 3% of patients or greater included headache, vasomotor symptoms, mood disorders, abnormal uterine bleeding, nausea, toothache, back pain, decreased sexual desire and arousal, arthralgia, fatigue, and dizziness. Serious adverse reactions occurring in up to 3% of patients included uterine hemorrhage, suicidal ideation, cholelithiasis, and cholecystitis.^[Ref]

Cardiovascular

• Common (1% to 10%): Hot flush, new/worsening hypertension
• Rare (0.01% to 0.1%): Thromboembolic events (deep vein thrombosis [DVT], pulmonary embolism [PE])

Postmarketing reports for relugolix monotherapy: Thromboembolic events^[Ref]

Dermatologic

• Common (1% to 10%): Alopecia/hair loss/hair thinning, hyperhidrosis, night sweats
• Uncommon (0.1% to 1%): Angioedema, urticaria

Postmarketing reports, including relugolix monotherapy: Drug eruption^[Ref]

Gastrointestinal

• Common (1% to 10%): Dyspepsia, nausea, toothache, diarrhea^[Ref]

Genitourinary

• Very common (10% or more): Resumption of menstruation after drug discontinuation (up to 100%), amenorrhea (up to 71%), irregular bleeding pattern (32%), cyclic bleeding (15%)
• Common (1% to 10%): Abnormal uterine bleeding (menorrhagia, metrorrhagia, vaginal hemorrhage, uterine hemorrhage, polymenorrhea, and menstruation irregular), vulvovaginal dryness
• Uncommon (0.1% to 1%): Uterine myoma expulsion, uterine leiomyoma (prolapse), pelvic pain

Postmarketing reports, including relugolix monotherapy: Uterine leiomyoma degeneration^[Ref]

Hepatic

• Uncommon (less than 1%): Elevated AST and/or ALT greater than 3 times the upper limit of normal
• Frequency not reported: Gallbladder disease, cholelithiasis and cholecystitis^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylactoid reaction^[Ref]

Musculoskeletal

• Very common (10% or more): Decline in lumbar spine bone mineral density (up to 23%)
• Common (1% to 10%): Back pain, arthralgia, bone loss
• Uncommon (0.1% to 1%): Low trauma fractures^[Ref]

In some women who had normal bone mineral density (BMD) at start of treatment with this drug, a bone loss varying from greater than 3 to 8% was reported.^[Ref]

Nervous system

• Very common (10% or more): Headache (33%)

Other

• Very common (10% or more): Decreased high-density lipoprotein (HDL) cholesterol (up to 22.2%), vasomotor symptoms including hot flush, hyperhidrosis, night sweats, and flushing (up to 13%), increased total cholesterol (up to 13.7%)
• Common (1% to 10%): Increased low-density lipoprotein (LDL) cholesterol, breast cyst, fatigue, peripheral edema^[Ref]

Psychiatric

• Common (1% to 10%): Decreased sexual desire and arousal (libido decreased, libido disorder, loss of libido, female sexual arousal disorder), mood disorders (affect lability, affective disorder, anxiety, depressed mood, mood swings, depression, emotional distress, generalized anxiety disorder, irritability, mixed anxiety and depressive disorder, mood altered, mood swings, suicidal ideation)^[Ref]

Respiratory

• Frequency not reported: Pulmonary embolism^[Ref]

See also:

Frequently asked questions

• Does Myfembree shrink fibroids?

Further information

Myfembree side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer