From the Guidelines
Estrogen doses for transgender women should be individualized, but typically include oral estradiol (2-6 mg daily), estradiol valerate injections (5-20 mg every 1-2 weeks), or transdermal estradiol patches (0.1-0.4 mg/day), with a preference for transdermal administration due to its better safety profile and more physiological serum estradiol concentrations 1.
Key Considerations
- The goal of estrogen therapy is to achieve female-typical estrogen levels (100-200 pg/mL) while maintaining testosterone at female ranges (less than 50 ng/dL) 1.
- Estrogen therapy should be combined with anti-androgens like spironolactone (100-300 mg daily) or cyproterone acetate (10-50 mg daily) to suppress testosterone production.
- Treatment should be individualized, with regular blood tests to monitor hormone levels, liver function, and other health parameters.
- Estrogen therapy carries risks including blood clots, cardiovascular issues, and liver problems, so regular medical supervision is essential 1.
Administration Routes
- Transdermal administration of estrogen is preferred due to its better safety profile and more physiological serum estradiol concentrations 1.
- Oral estrogen preparations have a higher risk of venous thromboembolism compared to transdermal or transvaginal routes 1.
Monitoring and Follow-up
- Regular blood tests should be performed to monitor hormone levels, liver function, and other health parameters.
- Patients should discuss their specific health history with healthcare providers to determine the most appropriate regimen, as factors like age, weight, and existing health conditions can affect dosing needs.
- Physical changes typically begin within 3-6 months, with maximum effects taking 2-3 years.
From the Research
Estrogen Doses for Transgender Women
- The goal of gender-affirming hormone therapy (GAHT) for transgender women is to use estradiol to suppress endogenous production of testosterone 2.
- A study comparing different GAHT regimens found that transdermal 17-beta estradiol resulted in more rapid suppression of total testosterone and lower estrone levels compared to sublingual estradiol 2.
- The study also found that most transgender women achieved cisgender women testosterone levels within 2 months on 1 or 2 0.1 mg/24 hours estradiol patches 2.
- Another study found that exogenous estrogen is used in transgender women to help feminize patients, and anti-androgens are used as adjuncts to help suppress masculinizing features 3.
- The effective dose of estradiol for estrogen replacement therapy in postmenopausal women is daily doses of 0.2 mg and less, which achieves estradiol plasma concentrations of at least 35-55 pg/ml 4.
Route of Administration
- The route of administration of estradiol can affect the efficacy and safety of the treatment, with transdermal administration resulting in more constant plasma concentrations compared to oral or sublingual administration 2, 4.
- A study found that parenteral estrogen administration, such as vaginal or percutaneous creams, intranasal solutions, and sublingual tablets, results in a pronounced, transient elevation of plasma concentrations of estradiol and a minor increase of estrone 4.
Monitoring and Safety
- Bone and cardiovascular health are important considerations in transgender patients on long-term hormones, and care should be taken to monitor certain metabolic indices while patients are on cross-sex hormone therapy 3, 5.
- Existing epidemiological data suggest that the use of certain estrogens in trans women induces an increased risk of myocardial infarction and stroke, highlighting the need for lifestyle management as an integral part of trans health care 5.