ESTRING® Description

(estradiol)

DESCRIPTION

ESTRING (estradiol vaginal system) is a slightly opaque ring with a whitish core containing a drug reservoir of 2 mg estradiol. Estradiol, silicone polymers, barium sulfate and silicone fluid (as dispersing agent) are combined to form the ring. When placed in the vagina, ESTRING releases estradiol, approximately 7.5 mcg per day, in a consistent stable manner over 90 days. ESTRING has the following dimensions: outer diameter 55 mm; cross-sectional diameter 9 mm; core diameter 2 mm. One ESTRING should be inserted into the upper third of the vaginal vault, to be worn continuously for three months.

Estradiol is chemically described as estra-1, 3, 5(10)-triene-3, 17β-diol. The molecular formula of estradiol is C18H24O2 and the structural formula is:

Chemical Structure

The molecular weight of estradiol is 272.39.

Find ESTRING® medical information:

Find ESTRING® medical information:

Our scientific content is evidence-based, scientifically balanced and non-promotional. It undergoes rigorous internal medical review and is updated regularly to reflect new information.

ESTRING® Quick Finder

Prescribing Information
Download Prescribing Information

Health Professional Information

Description

DESCRIPTION

ESTRING (estradiol vaginal system) is a slightly opaque ring with a whitish core containing a drug reservoir of 2 mg estradiol. Estradiol, silicone polymers, barium sulfate and silicone fluid (as dispersing agent) are combined to form the ring. When placed in the vagina, ESTRING releases estradiol, approximately 7.5 mcg per day, in a consistent stable manner over 90 days. ESTRING has the following dimensions: outer diameter 55 mm; cross-sectional diameter 9 mm; core diameter 2 mm. One ESTRING should be inserted into the upper third of the vaginal vault, to be worn continuously for three months.

Estradiol is chemically described as estra-1, 3, 5(10)-triene-3, 17β-diol. The molecular formula of estradiol is C18H24O2 and the structural formula is:

Chemical Structure

The molecular weight of estradiol is 272.39.

Medication Guide

Health Professional Information

{{section_name_patient}}

{{section_body_html_patient}}

Resources

Didn’t find what you were looking for? Contact us.

MI Digital Assistant

Chat online with Pfizer Medical Information regarding your inquiry on a Pfizer medicine.

Call 800-438-1985*

*Speak with a Pfizer Medical Information Professional regarding your medical inquiry. Available 9AM-5Pm ET Monday to Friday; excluding holidays.

Medical Inquiry

Submit a medical question for Pfizer prescription products.

Report Adverse Event

Pfizer Safety

To report an adverse event related to the Pfizer-BioNTech COVID-19 Vaccine, and you are not part of a clinical trial* for this product, click the link below to submit your information:

Pfizer Safety Reporting Site

*If you are involved in a clinical trial for this product, adverse events should be reported to your coordinating study site.

If you cannot use the above website, or would like to report an adverse event related to a different Pfizer product, please call Pfizer Safety at (800) 438-1985.

FDA Medwatch

You may also contact the U.S. Food and Drug Administration (FDA) directly to report adverse events or product quality concerns either online at www.fda.gov/medwatch or call (800) 822-7967.