Side Effects of Estriol

Updated April 17, 2017

Estriol is sometimes used as an alternative hormone therapy for women seeking relief from menopausal health issues. A controversial hormone, estriol in oral form can have potentially serious side effects that should be considered with a medical practitioner before use. In topical use, mild side effects are also reported.

What is Estriol?

Estriol is a hormone produced by the placenta, the tissue connecting the foetus to the mother during pregnancy. Normally created in small quantities in females, estriol production increases progressively during the few months of pregnancy so the body does not reject the foetus as a foreign object. Estriol has been used in Europe and Asia as a hormone replacement therapy for women experiencing menopausal symptoms. According to the Journal of Infectious Diseases, the U.S. Food and Drug Administration has not approved estriol for hormone therapy in the U.S.

Medicinal Uses

In the U.S., estriol has been used in alternative medicine for a variety of menopausal health issues; as a topical cream, estriol is used for post-menopausal vaginitis. In research analysis conducted at Haemek Medical Center, in Afula, Israel, the effectiveness of estriol was analysed in oral form for the treatment of urinary tract infections in post menopausal women with favourable results. There has been ongoing research in the U.S. analysing long-term effects of estriol as an alternative hormone therapy, and UCLA has reported research efforts to review estriol as a potential treatment for multiple sclerosis.

Pre-Existing Conditions and Side Effects

Estriol is not recommended for use when pre-existing conditions are present. Women with a history of estriol, soy or peanut allergies may experience dizziness, swelling, skin inflammation, flushed skin or rashes. Women with heart conditions such as previous heart attack, high blood pressure, thrombosis or heart disease may experience heart palpitations, increased blood pressure or increased clotting. Women with hormone production or uterine conditions such as fibroids or endometriosis may suffer from increased or painful urination, breast tenderness, abdominal pain and spotting, according to WebMD.

Bioidentical Hormone Therapy Side Effects

Synthetic estriol is used in prescription form in the United States in bioidentical hormone therapy, an alternative to traditional FDA approved hormone therapy. Available by prescription under the brand names Biest or Triest, bioidentical hormone therapy commonly reported side effects include breast tenderness, fluid retention, diarrhoea, and uterine breakthrough bleeding or clot formation. The FDA has also indicated that bioidentical hormones may possess similar effects or risks associated with traditional hormone therapy. These hazards may include increased risk of heart disease, breast cancer or dementia in some women, according to the FDA.

Cancer Risks and Considerations

Estriol simulates breast cancer cell growth more than other oestrogen. In studies on menopausal women, breast tissue from women with breast cancer demonstrates higher levels of estriol than those without breast cancer. In 2001, The Journal of Infectious Diseases published study results indicating elevated endometrial cancer risks associated with estriol taken in oral form. For alternative hormone therapy, research suggests patients counter the potential cancer hazards of estriol with the hormone progesterone to manage health risks.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

CL Hardy is a communication professional based in Austin, Texas. In addition to writing corporate newsletters, proposals and technical white papers for Fortune 500 clients for more than 12 years, Hardy has been published in "Black Collegian" magazine; her articles on human resources, business and art topics can be found on eHow. She graduated from the University of Pennsylvania with a B.S. in communication.