Gender-affirming hormone therapy
Gender-affirming hormone therapy, also known as hormone replacement therapy or transgender hormone therapy, is a form of hormone therapy in which sex hormones and other hormonal medications are administered to transgender or gender nonconforming individuals for the purpose of more closely aligning their secondary sexual characteristics with their gender identity. This form of hormone therapy is given as one of two types, based on whether the goal of treatment is masculinization or feminization:
- Masculinizing hormone therapy – for transgender men or transmasculine people; consists of androgens and occasionally antiestrogens.
- Feminizing hormone therapy – for transgender women or transfeminine people; consists of estrogens with or without antiandrogens.
Non-binary people may also engage in hormone therapy in order to achieve a desired balance of sex hormones or to help align their bodies with their gender identities. Many transgender people obtain hormone replacement therapy from a licensed health care provider, while others obtain and self-administer hormones.
History
Requirements
The formal requirements to begin gender-affirming hormone therapy vary widely depending on geographic location and specific institution. Gender-affirming hormones can be prescribed by a wide range of medical providers including, but not limited to, primary care physicians, endocrinologists, and gynecologists. Requirements to be prescribed these hormones generally include a minimum age. According to the Endocrine Society, there has been little research on taking cross-sex hormones before the age of about 14.Historically, many health centers required a psychiatric evaluation and/or a letter from a therapist before beginning hormone replacement therapy. Many centers now use an informed consent model that does not require any routine formal psychiatric evaluation, but rather focuses on reducing barriers to care while ensuring a person can understand the risks and benefits of treatment. Some LGBT health organizations, including Chicago's Howard Brown Health Center and Planned Parenthood, advocate for this type of informed consent model.
The World Professional Association for Transgender Health Standards of Care, 7th edition, note that both of these approaches to care are appropriate.
Gender dysphoria
Many international guidelines and institutions require persistent, well-documented gender dysphoria as a pre-requisite to starting gender-affirmation therapy. Gender dysphoria refers to the psychological discomfort or distress that an individual can experience if their sex assigned at birth is incongruent with that person's gender identity. Signs of gender dysphoria can include comorbid mental health stressors such as depression, anxiety, low self-esteem, and social isolation. Not all gender nonconforming individuals experience gender dysphoria, and measuring a person's gender dysphoria is critical when considering medical intervention for gender nonconformity.Treatment options
Guidelines
For transgender youth, the Dutch protocol existed as among the earlier guidelines for hormone therapy by delaying puberty until age 16. The World Professional Association for Transgender Health and the Endocrine Society later formulated guidelines that created a foundation for health care providers to care for transgender patients. UCSF guidelines are also sometimes used. There is no generally agreed-upon set of guidelines, however.Delaying puberty in adolescents
Adolescents experiencing gender dysphoria may opt to undergo puberty-suppressing hormone therapy at the onset of puberty. The Standards of Care set forth by WPATH recommend individuals pursuing puberty-suppressing hormone therapy wait until at least experiencing Tanner Stage 2 pubertal development. Tanner Stage 2 is defined by the appearance of scant pubic hair, breast bud development, and/or slight testicular growth. WPATH classifies puberty-suppressing hormone therapy as a "fully reversible" intervention. Delaying puberty allows individuals more time to explore their gender identity before deciding on more permanent interventions and prevents the physical changes associated with puberty.The preferred puberty-suppressing agent for both individuals assigned male at birth and individuals assigned female at birth is a GnRH Analogue. This approach temporarily shuts down the Hypothalamic-Pituitary-Gonadal Axis, which is responsible for the production of hormones that cause the development of secondary sexual characteristics in puberty.
According to a study by JAMA Pediatrics published in January of 2025, less than 0.1% of adolescents covered by private medical insurance in the US take gender-affirming medication to treat gender dysphoria.
Feminizing hormone therapy
is typically used by transgender women, who desire the development of feminine secondary sex characteristics. Individuals who identify as non-binary may also opt-in for feminizing hormone treatment to better align their body with their desired gender expression. Feminizing hormone therapy usually includes medication to suppress testosterone production and induce feminization. Types of medications include estrogens, antiandrogens, and progestogens. Most commonly, an estrogen is combined with an antiandrogen to suppress and block testosterone. This allows for demasculinization and promotion of feminization and breast development. Estrogens are administered in various modalities including injection, transdermal patch, and oral tablets.The desired effects of feminizing hormone therapy focus on the development of feminine secondary sex characteristics. These desired effects include: breast tissue development, redistribution of body fat, decreased body hair, reduction of muscle mass, and more. The table below summarizes some of the effects of feminizing hormone therapy in transgender women:
Masculinizing hormone therapy
is typically used by transgender men, who desire the development of masculine secondary sex characteristics. Masculinizing hormone therapy usually includes testosterone to produce masculinization and suppress the production of estrogen. Treatment options include oral, subcutaneous injections or implant, and transdermal. Dosing is patient-specific, depending on the patient's rate of metabolism, and is discussed with the physician. The most commonly prescribed methods are intramuscular and subcutaneous injections. This dosing can be daily, weekly or biweekly depending on the route of administration and the individual patient.Unlike feminizing hormone therapy, individuals undergoing masculinizing hormone therapy do not usually require additional hormone suppression such as estrogen suppression. Therapeutic doses of testosterone are usually sufficient to inhibit the production of estrogen to desired physiologic levels.
The desired effects of masculinizing hormone therapy focus on the development of masculine secondary sex characteristics. These desired effects include: increased muscle mass, increased bone turnover, development of facial hair, voice deepening, increase and thickening of body hair, and more.
| Effect | Time to expected onset of effect | Time to expected maximum effect | Permanency if hormone therapy is stopped | Sources |
| Skin oiliness and acne | 1-6 months | 1–2 years | Reversible | |
| Facial and body hair growth | 1-12 months | 1-5 years | Permanent | |
| Scalp hair loss | 6-12 months | Variable | Permanent | |
| Increased muscle mass | 6-12 months | 2-5 years | Reversible | |
| Body fat redistribution | 1-6 months | 2-5 years | Reversible | |
| Cessation of menses | 1-6 months | - | Reversible | |
| Clitoral enlargement | 1-12 months | 1-2 years | Permanent | |
| Deepened voice | 1-12 months | 1-2 years | Permanent | |
| Increased sex drive | Variable | Variable | Reversible |
Safety
Hormone therapy for transgender individuals has been shown in medical literature to be generally safe, when supervised by a qualified medical professional. There are potential risks with hormone treatment that will be monitored through screenings and lab tests such as blood count, kidney and liver function, blood sugar, potassium, and cholesterol. Taking more medication than directed may lead to health problems such as increased risk of cancer, heart attack from thickening of the blood, blood clots, and elevated cholesterol. Hormone therapy has been shown to improve the psychosocial well-being, and lower levels of distress among transgender individuals.Feminizing hormone therapy
The Standards of Care published by the World Professional Association for Transgender Health summarize many of the risks associated with feminizing hormone therapy.Masculinizing hormone therapy
The Standards of Care published by the World Professional Association for Transgender Health summarize many of the risks associated with masculinizing hormone therapy.| Likely increased risk | Possible increased risk | Inconclusive/no increased risk |
| Polycythemia | Type 2 diabetes | Osteoporosis |
| Weight gain | Breast cancer | |
| Acne | Ovarian cancer | |
| Pattern hair loss | Uterine cancer | |
| Hypertension | Cervical cancer | |
| Sleep apnea | ||
| Decreased HDL cholesterol | ||
| Increased LDL cholesterol | ||
| Cardiovascular disease | ||
| Hypertriglyceridemia |