Gender-Affirming Hormone Therapy

Gender-affirming hormone therapy is a treatment used by some transgender and gender-diverse people to align certain physical characteristics with their gender. This page describes, in neutral terms, what it is, how it generally works, the common forms, how it is monitored, and the considerations to discuss with a clinician.

What gender-affirming hormone therapy is

Gender-affirming hormone therapy adjusts a person's hormone levels so that some physical features develop in a direction consistent with their gender identity. It works with the body's existing endocrine pathways: sex hormones such as estrogen and testosterone shape many secondary sex characteristics, and changing their balance gradually shifts some of those characteristics. Broadly, the therapy falls into two approaches: feminizing therapy, which generally uses estrogen and often a medication to reduce testosterone effects, and masculinizing therapy, which generally uses testosterone.

The aim is to support a person's wellbeing and goals rather than to treat an illness. Because the changes unfold over months to years and differ between individuals, an early and honest conversation about what therapy can and cannot do is an important part of starting. Some people pursue a full set of available changes, while others seek only some; the approach is shaped around the individual.

Who it may be considered for

Therapy is generally considered for adults who seek physical changes consistent with their gender, after an assessment that includes a discussion of goals, expectations, health history, and informed consent. Care is often delivered within a supportive framework that may involve more than one clinician — for example primary care, endocrinology, and mental health support — and many guidelines emphasise individualized, person-centred care. A clinician also reviews existing health conditions, medications, and family history that may affect how therapy is approached.

Decisions for younger people involve additional considerations and specialist involvement, and approaches vary by region and clinical setting. Because needs and goals differ widely, there is no single path. A clinician helps each person understand the likely timeline, which effects tend to be gradual, which become settled, and which may be limited, so that expectations are realistic before starting.

How it generally works

Feminizing therapy raises estrogen and lowers the effects of testosterone. Over months, this can lead to changes such as softer skin, some breast development, a shift in body fat distribution, and reduced oiliness; effects on body and facial hair tend to be more limited, and some features established during an earlier puberty do not reverse. Masculinizing therapy raises testosterone, which over months can lead to a deeper voice, increased body and facial hair, changes in body composition, and cessation of menstruation. Certain testosterone-driven changes, such as voice deepening, tend to become settled over time.

This table is illustrative and general; the pace, extent, and combination of effects vary widely, and a clinician explains what is realistic for an individual.

Common forms and routes

Hormones can be delivered by several routes, chosen between a person and their clinician based on preference, health factors, and practicality. Described generally:

• Estrogen may come as tablets, skin patches, gels, or injections; the route can influence convenience and how the body processes the hormone.
• Medications that reduce testosterone effects are sometimes used alongside estrogen, depending on the regimen.
• Testosterone may come as gels, injections, or patches.

This page does not discuss doses, which are determined individually by a prescriber. The choice of route can affect convenience, how steady levels remain between doses, and which monitoring a clinician recommends. Some people change route over time as preferences or circumstances change, which is part of the ongoing conversation with a clinician.

Timeline and expectations

Hormone therapy is gradual rather than sudden. Some changes, such as shifts in skin texture or oiliness and changes in mood or libido, can begin within the first weeks to months, while others, such as breast development, fat redistribution, or facial hair growth, develop over a longer period and may continue to evolve for a couple of years. A clinician can describe the general sequence and explain that the final extent of any change differs between individuals and cannot be predicted precisely. Setting realistic expectations early helps people make informed choices and judge progress without undue pressure.

How clinicians typically monitor it

Monitoring helps keep therapy within a sensible range and supports safety over time. It commonly includes:

• Blood tests to check hormone levels and bring them toward a target range for the chosen direction of therapy.
• General health checks, which may include blood pressure, blood count, liver-related markers, and blood lipids depending on the regimen.
• Review of physical changes, wellbeing, mood, and any side effects.
• Discussion of preventive care and screening that remains relevant to a person's anatomy and history.

Monitoring is usually more frequent at the start and then spaced out as levels stabilize. The schedule is tailored to the individual and the chosen approach.

Known considerations and risks

Like any hormone therapy, gender-affirming therapy carries considerations that are weighed individually rather than applied uniformly. Depending on the regimen, these can include effects on blood clot risk, blood pressure, blood lipids, red blood cell concentration, and effects on fertility. Pre-existing conditions such as a history of clots, cardiovascular disease, or certain hormone-sensitive conditions, as well as smoking and other medications, are taken into account when planning and reviewing therapy.

Because therapy can reduce fertility, sometimes in ways that may not fully return, clinicians generally discuss options for preserving the ability to have biological children before starting, for those who may want it. The pace and extent of physical change vary from person to person, and some changes become settled while others are limited or partly reversible if therapy stops. Long-term outcomes continue to be studied, so clinicians generally take an individualized, ongoing approach and review therapy over time.

Bone health and general wellbeing are also part of long-term care, since sex hormones influence bone and other systems; this is one reason monitoring and periodic review continue rather than stopping once initial changes settle. People are encouraged to report new or concerning symptoms between appointments so the plan can be adjusted. None of this is a substitute for an individual assessment, which weighs a person's full health picture against their goals.

Shared decision-making

Gender-affirming care is grounded in shared decision-making, with goals, expectations, and trade-offs discussed openly with a clinician. Informed consent — understanding the likely effects, the uncertainties, and the considerations — is central. You can read related material in our hormones and conditions sections, learn about testing under blood tests, and compare other options in the treatments overview.