Menopause Home > Specific Safety Concerns With Premarin

Specific Precautions and Warnings for Premarin

Some of the warnings and precautions to be aware of prior to using Premarin include the following:
  • Studies have shown that estrogen hormone replacement therapy (such as Premarin) increases the risk of strokes and blood clots in the legs. Studies have also shown that estrogen plus progestin hormone replacement therapy increases the risks of heart attacks, strokes, and blood clots in the legs and lungs. In no case should Premarin be used to prevent heart disease (see Hormone Replacement Therapy and Heart Health for more information).
  • Your healthcare provider should make sure that you are appropriately treated for any risk factors for heart disease (such as high blood pressure, high cholesterol, diabetes, obesity, or smoking) or blood clots before you take Premarin.
  • When possible, Premarin should be stopped four to six weeks before many surgeries, in order to help prevent blood clots.
  • For women who still have a uterus (who have not had a hysterectomy), taking Premarin alone (without a progestin) increases the risk of endometrial cancer, which is cancer of the lining of the uterus. Women who still have a uterus should take Premarin with a progestin (which can be taken separately or in a combination product such as Prempro® or Premphase®).
  • Let your healthcare provider know if you have abnormal vaginal bleeding (such as very heavy bleeding or bleeding between periods) while taking Premarin, as this may be a sign of precancerous or cancerous changes in the uterus. Your healthcare provider can perform the necessary tests to rule out cancer.
  • Estrogen drugs (such as Premarin) used with or without a progestin may increase the risk of breast cancer. Proper screening and monitoring (as determined by your healthcare provider), such as yearly mammograms and monthly self breast exams, is recommended.
  • Estrogen drugs (such as Premarin) used with or without a progestin seem to increase the risk of dementia. In no case should Premarin be used to prevent or treat dementia (it is not effective for this use).
  • Women who take estrogen (such as Premarin) have an increased risk for gallbladder disease.
  • Let your healthcare provider know right away if you notice any vision changes. This can signal a blood clot in the retina, a possible side effect of Premarin.
  • Premarin can cause high blood pressure (hypertension) or high triglycerides in some women. Your healthcare provider should monitor you for these problems.


  • There have been reports of very serious allergic reactions to Premarin. Some of these reactions involved swelling of the tongue and throat, potentially interfering with breathing. Women who have had such reactions to Premarin in the past should not take this drug ever again. 


  • If you have had jaundice (yellowing of the whites of the eyes or skin) due to estrogens or pregnancy in the past, it is possible that Premarin will cause similar problems to recur. If this happens, your healthcare provider will probably advise you to stop taking Premarin.


  • If you see something that resembles a Premarin tablet in your stool, please consult your healthcare provider. 


  • If you have an underactive thyroid (hypothyroidism), Premarin may increase your body's requirement for thyroid hormones. Your healthcare provider should monitor you and adjust the dose of your thyroid medications as necessary.
  • Premarin can cause fluid retention. This can cause problems for people with congestive heart failure (CHF) or kidney problems.
  • Premarin should be used with caution in people who have low calcium levels in the blood (known medically as hypocalcemia).
  • It is not clear if Premarin increases the risk of ovarian cancer. Some studies have shown an increased risk, while others have not.
  • Premarin can make endometriosis symptoms worse.
  • Premarin can interact with a number of different medications (see Premarin Drug Interactions for more information).
  • Premarin should not be used during pregnancy (see Premarin and Pregnancy).
  • Premarin does pass through breast milk. Therefore, if you are breastfeeding or plan to start breastfeeding, discuss this with your healthcare provider prior to taking the drug (see Premarin and Breastfeeding).
Written by/reviewed by:
Last reviewed by: Kristi Monson, PharmD;
Last updated/reviewed:
List of references (click here):
Other Articles in This eMedTV Presentation

Topics & Medications


Related Channels

eMedTV Links
Copyright © 2006-2020 Clinaero, Inc.

eMedTV serves only as an informational resource. This site does not dispense medical advice or advice of any kind. Site users seeking medical advice about their specific situation should consult with their own physician. Click Terms of Use for more information.

This site complies with the HONcode standard for trustworthy health information:
verify here.