Androgen Effects on the Reproductive Neuroendocrine Axis, 2025 Version

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