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Effect of Estrogen Treatment on Drug Metabolism and Transport

Effect of Estrogen Treatment on Drug Metabolism and Transport

Gender-affirming hormone therapy may include estradiol, a hormone that the body creates and uses naturally. Estradiol is prepared as a medication that patients may take to increase hormone levels. Changes in estradiol concentrations in the body may affect how the body processes other medicines. The purpose of this study is to find out how estradiol therapy affects a single tracer dose of approved medicines in the blood (midazolam, digoxin, and acetaminophen) and to confirm estradiol treatment does not affect natural bacterial in the gut.

Participant Eligibility

Inclusion Criteria:1) Self-identified trans* adult at least 18 years of age.2) Not taking estrogen treatment currently.3) Transgender adults planning to take oral or injectable estradiol treatment.Exclusion Criteria:1) Unwilling/unable to return for project follow-up visits.2) Unwilling/unable to provide written informed consent.


Lauren Cirrincione
(650) 353-7782

Additional Study Details

Full Study Title
Effect of gender-affirming estrogen therapy on drug metabolism, transport, and gut microbiota

Study ID: 14091
Start Date: 11/01/2022
End Date: 01/31/2024

Lauren Cirrincione, PharmD (she/her)

Accepts Healthy Volunteers?

Study Site(s)


1959 NE Pacific St
Seattle, Washington 98195


Use the link below to send a message to the study coordinator, or call the number above to speak directly with a study representative.

I am interested in this research study.