What are the risks of using estradiol?

ENDOMETRIAL CANCER: Women who take estradiol are at a higher risk of endometrial cancer (cancer in the lining of the uterus). The risk is higher in those who take estradiol for a prolonged duration at high doses. In women who still have a uterus, doctors usually prescribe another female sex hormone called progestin along with estradiol to lower this risk. Tell your doctor if you have unusual vaginal bleeding that does not stop or keeps coming back while you are on estradiol - this can be a warning sign of endometrial cancer. 

BREAST CANCER: Taking estradiol is associated with a higher risk of hormone-related cancer. Tell your doctor if you have a personal or family medical history of breast cancer. The risk of breast cancer is higher when estradiol is taken for a long time. You can lower the risk of breast cancer by taking the lowest possible dose for the shortest period of time. Tell your doctor if you notice any abnormal lumps, swelling, or pain in your breasts. You should know that in some people, estradiol is used to treat breast cancer and prostate cancer (a cancer of the male reproductive tract). 

HEART DISEASE: Women who take estradiol either alone or in combination with progestin are at a higher risk of heart disease and heart attack. This risk is greater in people who have a history of high blood pressure, high cholesterol, obesity, or smoking. Get emergency medical care if you have heart attack symptoms such as chest tightness, stabbing chest pain, difficulty breathing, fast heartbeat, dizziness, sweating, nausea, and vomiting.

RISK OF BLOOD CLOTS AND STROKE: Taking estradiol is associated with an increased risk of blood clots in the lungs (pulmonary embolism), blood clots in the legs (deep vein thrombosis), and stroke in postmenopausal women. The risk of blood clots is higher in women who sit or rest for long periods without walking. Your doctor may recommend stopping estradiol 4-6 weeks before certain surgeries due to a higher risk of blood clots. Seek immediate medical help if you have any pain, cramps, swelling, or muscle tightness in one or both legs. Also, seek emergency medical care for chest pain, cough, or trouble breathing. These can be signs of blood clots in the legs and lungs, respectively. Also, seek emergency medical attention if you have signs of a stroke, such as numbness, weakness, slurred speech, blurred vision, dizziness, headache, trouble walking, loss of balance, or confusion.

DEMENTIA: Women over the age of 65 who are on estradiol have a higher risk of developing dementia. Tell your doctor if you or your family members notice forgetfulness, confusion, anxiety, or trouble with decision-making or problem-solving. 

LIVER AND GALLBLADDER PROBLEMS: Postmenopausal women on estradiol are at an increased risk of gallbladder problems that may even require surgery. This medication should be used with caution in women who have a history of liver disease or past liver problems with estrogen use or pregnancy. Tell your healthcare provider if you experience stomach pain, swelling, shoulder pain, back pain, yellowing of the skin and eyes (jaundice), dark-colored urine, nausea, vomiting, or loss of appetite.

CALCIUM LEVELS: In some people with breast cancer or cancer that has spread to the bones, taking estradiol can lead to dangerously high calcium levels. Symptoms may include unusual thirst, nausea, vomiting, constipation, stomach pain, muscle weakness, bone pain, or confusion. Tell your doctor if you have any of these symptoms. If you have low calcium levels, you should take estradiol with caution. Tell your doctor if you experience symptoms of low calcium such as tingling or burning in the lips, fingers, or toes, muscle cramps, muscle pain, or confusion.

VISION DIFFICULTIES: Estradiol is associated with an increased risk of blood clots in the eye (this condition is called retinal vascular thrombosis). Stop taking estradiol and call your doctor without delay if you have trouble seeing out of one or both eyes, double vision, bulging eyes, or migraines.

HIGH TRIGLYCERIDE LEVELS: Estradiol can lead to elevated triglyceride levels (this is a type of fat found in your blood). Tell your doctor if you have a history of high triglycerides. Dietary changes can help to bring your triglyceride levels down. 

FLUID RETENTION: Estradiol can lead to edema or fluid retention. The risk is higher in women who have a history of heart disease or kidney disease. Tell your doctor if you notice unusual swelling anywhere in your body or sudden weight gain. 

HYPOTHYROIDISM: Estradiol can lower thyroid hormone levels (hypothyroidism or underactive thyroid disorder). If you are taking thyroid replacement therapy for low thyroid hormone levels, talk to your doctor about adjusting the dose - you might need higher doses of your thyroid replacement medication. Keep all your doctor’s appointments. Your doctor may perform blood tests periodically to keep an eye on your thyroid hormone levels.

WORSENING HEALTH CONDITIONS: Women who have health conditions like diabetes, asthma, lupus, seizures, or migraines should talk to their healthcare provider before taking estradiol. These health conditions can be made worse by taking estrogen products.  Your doctor or pharmacist can prescribe treatments other than hormone replacement therapy if you are at risk of complications from estradiol use.