MHMs Menopause Blog

Blood Clot Risk is lower for Estrogen-Only, Transdermal and Vaginal Estrogen Hormone Therapy

May 19, 2016 | By Julieann Roberts, Editor.

New research has found that blood clot risk is lower for estrogen-only, transdermal and vaginal estrogen hormone therapy, which is great news as the risk of blood clots in women increases with age.

Menopause, The Journal of North American Menopause Society (NAMS)  has published new research from the Karolinska Institute in Stockholm led by Dr. Annica Bergendal, which found that overall, estrogen-only therapy carries a lower risk of blood clots than treatment with a combination of estrogen and progestin, the synthetic version of progesterone.

According to Science Daily the study highlights that the way estrogen is delivered may impact the risks.  There was no increased risk of VTE (venous thromboembolism) in this study for women who used transdermal estrogen (such as patches), either alone or in combination with a progestogen. And women who used vaginal estrogen alone to ease vaginal dryness and other symptoms of genitourinary syndrome of menopause (GSM) also had no increased risk of VTE. Many menopause experts don’t expect vaginal estrogen to raise the risk because absorption into the bloodstream is small and results in levels similar to those in postmenopausal women who use no hormones. But studies on this question have been rare, noted the authors, so this finding is a big help for decision making.

This study adds to current knowledge that transdermal estrogen therapies are safer than oral and that different estrogen or progestogen combinations may have different risks.



Bergendal. A, MD., et al, (March 2016) Risk of venous thromboembolism associated with local and systematic use of hormone therapy in peri and postmenopaual women and in relations to type and route of administration. (Retrieved May 2016) Retrieved from

Blood Clot risk lower for estrogen-only, transdermal, and vaginal estrogen at menopause. (Retrieved May 2016) Retrieved from


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