How male-level testosterone affects reproductive hormone cycles in people assigned female at birth
Androgen Effects on the Reproductive Neuroendocrine Axis, 2025 Version
PHASE4 · University of California, San Diego · NCT07092527
This study will test whether male-level testosterone given to transgender men starting hormone therapy changes the ovarian and pituitary hormones that control menstrual cycles compared with cisgender women.
Quick facts
| Phase | PHASE4 |
|---|---|
| Study type | Interventional |
| Enrollment | 80 (estimated) |
| Ages | 18 Years to 35 Years |
| Sex | Female |
| Sponsor | University of California, San Diego (other) |
| Drugs / interventions | radiation |
| Locations | 1 site (San Diego, California) |
| Trial ID | NCT07092527 on ClinicalTrials.gov |
What this trial studies
Researchers will follow people assigned female at birth who are 18-35 years old, comparing those who plan to start testosterone therapy with untreated cisgender female controls. They will collect frequent blood samples to measure ovarian and pituitary reproductive hormones before and during testosterone cypionate treatment and perform periodic clinical exams and pelvic ultrasounds. The trial excludes people with pregnancy, known endocrine disease (including PCOS), extreme BMI, low hemoglobin, or other specified conditions. Data will characterize how chronic testosterone exposure alters hormone secretion patterns that regulate menstrual cyclicity.
Who should consider this trial
Good fit: Ideal candidates are 18-35 year olds assigned female at birth who have regular menstrual cycles and either plan to start testosterone therapy (transgender/non-binary group) or are cisgender women with regular cycles willing to serve as controls.
Not a fit: People who are pregnant, incarcerated, have untreated endocrine conditions (including PCOS), extreme BMI (<18 or >35), low hemoglobin, or are outside the 18-35 age range are excluded and would not benefit from participating.
Why it matters
Potential benefit: If successful, results could explain why testosterone causes menstrual changes and help guide safer, more predictable hormone regimens for transgender men.
How similar studies have performed: Clinical observations consistently report menstrual disruption with testosterone therapy, but detailed longitudinal hormonal studies like this are limited, so the approach is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: Transgender/Non-binary Group, Initiating Testosterone Group * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Aged 18-35 * Plan to initiate testosterone therapy * History of regular menstrual cycles (every 24-35 days) at baseline, before beginning TRT Inclusion Criteria: Cisgender Female Group * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Aged 18-35 * Having regular menstrual cycles (every 24-35 days) Exclusion Criteria: All * Pregnant * Incarcerated * Known cognitive impairment or institutionalized * Hemoglobin less than 11 gm/dl at screening evaluation * Weight less than 110 pounds * BMI \<18 or \>35 * Current endocrine disease- including untreated thyroid abnormalities, pituitary or adrenal disease, polycystic ovary syndrome, or androgen producing tumor * Current or recent pregnancy within two months of study enrollment * Current or recent breast feeding within two months of study enrollment * Diabetes, or renal, liver, or heart disease * History of oophorectomy or hysterectomy * History of radiation or surgery involving brain structures and/or pelvis/pelvic organs * Currently taking any medications that may affect their reproductive hormones, such as contraceptive medications, androgens, estrogens, progestins, gonadotropin-releasing hormone (GnRH) antagonists, insulinomimetics, and metformin. * History of prior testosterone therapy
Where this trial is running
San Diego, California
- University of California, San Diego — San Diego, California, United States (RECRUITING)
Study contacts
- Principal investigator: Antoni Duleba, MD — University of California, San Diego
- Study coordinator: Antoni Duleba, MD
- Email: aduleba@health.ucsd.edu
- Phone: 619-804-4765
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Transgenderism, Reproductive Issues