Transgender Hormone Therapy: Feminizing
The goal of hormone therapy in transfeminine patients is to reduce the endogenous effects of testosterone such as a coarse body hair and facial hair; and to induce feminine secondary sex characteristics such as breast and hip development, in keeping with the patient’s individual goals. Physiologically, this requires a suppression of endogenous androgens and the addition of estrogen.
- The anti-androgens typically used are spironolactone.
- If contraindications or intolerances exist for spironolactone, GnRH analogs (leuprolide or “Lupron”) may be considered. Finasteride is a less effective anti-androgen and is generally not recommended, but may be considered for those who desire very mild anti-androgenic effects.
- Following orchiectomy (+/- vaginoplasty), most transfeminine patients will not require androgen suppression. The androgen-blocker can be stopped immediately after surgery or tapered over the course of 4-6 weeks or more depending on risk.
- Estrogen acts directly on estrogen receptors to initiate feminization. Several forms and routes of estrogen have been used for feminization. At Biosymmetry, the most common form used is oral 17-β estradiol (Estrace). While conjugated estrogens (e.g. Premarin) have historically been used due to their accessibility/affordability, they are no longer recommended.
- There is a lack of consensus on the preferred timing of the initiation of estrogens in relation to an anti-androgen. Common approaches have included both the initiation of an anti- androgen (usually 1-3 months) prior to the addition of estrogen, or alternatively, the simultaneous introduction and subsequent titration of both components. The starting dose of estrogen can be maintained for 1-2 months, after which a dose increase can be considered barring any concerning effects. In patients over 50 years old who have been on estrogen for several years, doses may be reduced to those administered to post-menopausal cis women.
- The use of progestins in transfeminine patients continues to be controversial. There have been anecdotal reports of improved breast and/or areolar development, mood, sleep, and libido with the use of progestins; however a clear impact has yet to be demonstrated. Common side effects include weight gain, edema and depression. Given the lack of clear benefit, and potential risks, progestins are not routinely recommended as part of a feminizing hormone regimen. However, should patients request progestins, a trial may be considered following a frank discussion of expectations and risks.
What to expect from a regimen consisting of an anti- androgen and estrogen
The degree and rate of physical effects are largely dependent on patient-specific factors such as age, genetics, body habitus and lifestyle, and to some extent the dose and route used (selected in accordance with a patient’s specific goals and risk profile). Physical changes related to androgen blockade and estrogen may take months to appear and are generally considered to be complete after 2-3 years on hormone therapy. Breast growth is an aspect of feminization to which many transfeminine patients assign great importance. The degree of breast development is dependent on many factors, but most transfeminine patients experience modest breast development (average cup size less than A, or developmental Tanner stage 2 to 3). In early studies, neither type nor dosage of estrogen was shown to affect final breast size, and no relationship between serum estradiol levels and breast development was found.
Feminizing therapy does not affect the pitch of the voice in transfeminine patients. Some patients may obtain benefit from voice therapy with a qualified and supportive speech and language therapist who can work with the patient to modify their vocal characteristics. There are also a variety of surgical techniques that have been utilized to feminize the voice through alteration of the vocal cords.
- Unstable ischemic cardiovascular disease
- Estrogen-dependent cancer
- End stage chronic liver disease
- Psychiatric conditions which limit the ability to provide informed consent
- Hypersensitivity to one of the components of the formulation
Precautions and Risk Mitigation
Pre-existing medical conditions and risk factors may impart increased risks with estrogen administration and should be considered. Available measures to reduce associated risks should be considered and discussed prior to or concurrently with the initiation of hormone therapy.
*Individual results may vary.