Effect of Testosterone Treatment on Drug Metabolism and Transport

Effect of Gender-Affirming Testosterone Therapy on Drug Metabolism, Transport, and Gut Microbiota

This project will evaluate the effect of gender-affirming testosterone treatment on how other medications are processed by the body.

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

Inclusion Criteria:

• Self-identified trans* adult at least 18 years of age.
• Not taking testosterone treatment currently.
• Planning to start testosterone treatment through care provider for gender-affirming medical care.

Exclusion Criteria:

• Unwilling/unable to return for project follow-up visits.
• Unwilling/unable to provide written informed consent.