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Important safety information

What are the possible side effects from using MYFEMBREE?

These are not all the possible side effects you may have when taking MYFEMBREE. If you experience any side effects not listed here, tell your healthcare professional.

Side effects may include:

  • Back pain
  • Being irritable
  • Decreased interest in sex
  • Hair loss or hair thinning
  • Headache
  • Hot flushes
  • Increased sweating
  • Indigestion
  • Joint pain
  • Night sweats

MYFEMBREE can cause abnormal blood test results.

Uncommon serious side effects and what to do about them

Talk to your healthcare professional in all cases of the following uncommon side effects:

  • New or worsening depression, anxiety, or other mood changes
  • High blood pressure
  • Breast changes such as breast lumps or breast cancer: pain and tenderness, lumps, nipple discharge
  • Uterine myoma expulsion or prolapse (fibroid comes out either completely or partially through the vagina): usually with cramping and increased bleeding from the vagina
  • Cholestasis (gallbladder problems): jaundice (yellowing of the skin or whites of the eyes), dark urine, light-coloured stools

Talk to your healthcare professional only if you have a severe case of the following uncommon side effect:

  • Too much bleeding from the womb: abnormal vaginal bleeding, bleeding that lasts too long, that is too much, or is unexpected

Stop taking MYFEMBREE and get immediate medical help for the following uncommon side effects:

  • Thoughts of ending one’s life (suicidal ideation)
  • Pulmonary embolism (blood clot in the lung): sharp pain in the chest, coughing blood, sudden shortness of breath
  • Deep vein thrombosis (blood clot in the leg): pain in the calf, swelling, redness, skin feeling “warm to the touch”
  • Myocardial infarction (heart attack): crushing chest pain or heaviness, heartburn, shortness of breath, nausea, cold sweat, dizziness
  • Stroke: sudden, severe, or worsening headache, vomiting, dizziness, fainting, vision or speech problems, weakness or numbness in the arm or leg
  • Blood clot on the eye: sudden unexplained partial or complete loss of vision or double vision
  • Liver problems: yellowing of the skin or eyes, dark urine, feeling tired, nausea, vomiting, generalized swelling, right upper stomach pain or bruising
  • Allergic reactions: difficulty swallowing or breathing, wheezing, drop in blood pressure, feeling sick to your stomach and throwing up, hives or rash, swelling of the face, lips, tongue, or throat

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Who should not use MYFEMBREE?

Do not use MYFEMBREE if:

  • you are allergic to relugolix, estradiol, norethindrone acetate, or any of the other ingredients of this medicine or container
  • you have or have had blood clots in your legs (deep vein thrombosis), lungs (pulmonary embolism)
  • you have or have previously had a disease caused by blood clots in the arteries (such as a heart attack, stroke, or angina)
  • you have a blood clotting disorder (such as protein C deficiency, protein S deficiency, antithrombin-III deficiency, or Factor V Leiden)
  • you are 35 years of age or above and suffer from:
    • headaches with symptoms such as paralysis or loss of muscle control, or
    • migraines with visual disturbance
  • you have uncontrolled high blood pressure
  • you smoke and are over 35 years of age
  • you have osteoporosis
  • you have or suspect you have a history of breast cancer
  • you have, suspect you have, or had any type of hormone-sensitive cancer (e.g., endometrial cancer) or you have a higher risk developing a hormone-sensitive cancer
  • you have or ever had liver tumours
  • you have or ever had a liver disease and your liver function tests have not returned to normal
  • you are pregnant or think you might be pregnant. MYFEMBREE can cause early pregnancy loss
  • you are breastfeeding. Talk to your healthcare professional about the best way to feed your baby if you take MYFEMBREE
  • you are using hormonal birth control
  • you have any genital bleeding of unknown origin
  • you have partial or complete loss of vision from vascular eye disease
  • you have endometrial hyperplasia, which is when there is an irregular thickening of the uterine lining

What should I tell my doctor before taking MYFEMBREE?

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take MYFEMBREE. Talk about any health conditions or problems you may have, including if you:

  • have prediabetes or diabetes
  • have high triglycerides (fats) levels in blood
  • are scheduled for surgery or will be on bed rest. MYFEMBREE may increase your risk of blood clots after surgery. Your healthcare professional may advise you to stop taking MYFEMBREE 4 to 6 weeks before you have surgery. Talk to your healthcare professional about when to stop MYFEMBREE before surgery and when to restart MYFEMBREE after surgery
  • had gallbladder problems related to estrogen use or pregnancy
  • have or have had broken bones or other conditions that may cause bone problems, including taking any medications that may weaken your bones
  • have or have had depression, mood swings, or suicidal thoughts or behaviour
  • need a blood or urine test, because MYFEMBREE can affect the results of some tests, including thyroid, steroid, hormone, cholesterol, and blood clotting

What other warnings should I know about?

Taking MYFEMBREE can cause bone loss. Your healthcare professional may conduct an x-ray to monitor your bone health.
Taking MYFEMBREE may cause high blood pressure. See your healthcare professional to check your blood pressure regularly.
Taking MYFEMBREE can cause high blood sugar and cholesterol. Your healthcare professional will monitor your blood sugar and fat levels. They may stop your treatment if your fat levels are high. You may be at a great risk of developing pancreatitis if you already have high fat (triglyceride) levels in the blood.
Your healthcare professional may conduct a breast examination and mammography.
MYFEMBREE can decrease your menstrual bleeding or result in no menstrual bleeding at all, making it hard to know if you are pregnant. Watch for other signs of pregnancy such as breast tenderness, weight gain, and nausea.
Use non-hormonal birth control during your treatment and for one week after you end your treatment. Using an estrogen hormonal birth control may affect how MYFEMBREE works.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements, or alternative medicines.

The following may interact with MYFEMBREE:

  • erythromycin
  • rifampin

Throughout this website, the term “women” is used to mean cisgender women and individuals with female biology. Pfizer acknowledges the importance and need for more research into the challenges facing the transgender, genderfluid, and non-binary communities.