Hormone Replacement Therapy and Warfarin

Hormone replacement therapy, also known as HRT, is used to treat the symptoms of menopause and aging. Estrogen and progesterone, sometimes one or both, are prescribed during or after menopause. It is important to let your physician know if you are prescribed warfarin and you take hormone replacement therapy. The recommendations in this area are constantly being re-evaluated as more studies are being completed and evidence gathered. 

It had been common practice among healthcare providers to avoid prescribing HRT and anticoagulants at the same time, but this is changing. In a study conducted by Dr. Ida Martinelli, of the A. Bianchi Bonomi Hemophilia and Thrombosis Center in Milan in 2015, she found that “this trial provides some insight and reassurance that women can safely continue their hormones while being treated for blood clots”.1 Additional research by doctors Apostolakis, Olshansky and Lip in 2014 concluded that HRT does not independently predict adverse outcomes in patients with atrial fibrillation.2

Always let all of your health care providers know the complete list of medications you take and make sure you update them as changes are made.


  1. American Society of Hematology. Study: Women on Blood Thinners Can Take Hormone Therapy Without Increased Risk of Blood Clots and Bleeding. Blood. December 23, 2015. Retrieved from the website: www.hematology.org/Newsroom/Press-Releases/2015/4773.aspx.
  2. Apostolakis, S. et al. Hormone Replacement Therapy and Adverse Outcomes in Women with Atrial Fibrillation. Stroke. 2014;45:3076-3079.