HORMONE REPLACEMENT THERAPY
FOR TRANS TEENS
Hormone replacement therapy for trans teens means giving estrogen or testosterone to help an older adolescent develop physical features that align with their gender identity. It is a step for older adolescents, in later puberty, considered after a careful assessment and, for minors, with parental consent. It is separate from and later than puberty-pausing medication. Some of its effects are permanent, which is one reason the decision is made carefully and together with a young person, their family, and their providers. The therapy is monitored with regular follow-up, and its use among young people is uncommon.
Understanding what this treatment is, what it does, who it is for, and what is and is not reversible clears up much of the confusion around it. This page gives that picture in plain language and links to more detailed pages on each type of hormone and its effects. It uses "hormone therapy" or "gender-affirming hormone therapy" after the first mention; you may also see it called hormone replacement therapy or HRT, which refers to the same thing.
CONTENT NOTE
This is general information, not personal medical advice. Whether this medication is appropriate for a particular young person is a decision for that young person, their family, and their qualified healthcare providers, and in nearly all cases minors cannot receive it without parental consent. If you are in immediate danger, call 911; for support any time, call or text 988.
KEY TAKEAWAYS
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It's estrogen or testosterone. Hormone therapy uses one of these to develop physical features aligned with a young person's gender.
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It's for older adolescents. It is considered later in puberty, after assessment and, for minors, parental consent.
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It's a separate, later step. Hormone therapy is not the same as puberty-pausing medication; it comes later.
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Some effects are permanent. Certain changes do not reverse if the therapy stops, which is why the decision is careful.
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It's uncommon and monitored. Its use in youth is rare, and it is overseen with regular follow-up.
WHAT HORMONE THERAPY IS
Gender-affirming hormone therapy uses the sex hormones estrogen or testosterone to develop secondary sex characteristics that align with a young person's gender identity.
As a 2023 systematic review in Nature Human Behaviour describes, this therapy usually involves testosterone for transmasculine people and estrogen, along with a medication that lowers testosterone, for transfeminine people, with individualized approaches for nonbinary and gender-diverse people.
The hormones prompt the body to develop features typically associated with the person's gender over months to years.
TWO TYPES OF HORMONE THERAPY
There are two main forms, named for the direction of the changes they produce.
Feminizing Hormone Therapy:
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Estrogen, usually with a medication that lowers testosterone
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Develops softer skin, breast development, and a shift in body-fat distribution
Masculinizing Hormone Therapy:
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Testosterone
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Develops a deeper voice, facial and body hair, and more muscle
Sources: Endocrine Society (patient guidance); Cleveland Clinic; Nature Human Behaviour review (2023).
For the details on each, including timelines and what to expect, see testosterone therapy for transmasculine teens and estrogen therapy for transfeminine teens.
WHO IT IS FOR, AND WHEN
Hormone therapy is considered for older adolescents in later puberty, after careful assessment and with parental consent, and it is a separate step from puberty-pausing medication.
According to the Endocrine Society, hormones are added only after a multidisciplinary team has confirmed that gender dysphoria has persisted and that the young person has the capacity to give informed consent, a capacity it notes most adolescents reach by about age 16.
It is not the same decision as pausing puberty, which is an earlier, reversible step; hormone therapy comes later and is more significant. For how the steps fit together, see the steps of medical transition and how trans teens are assessed for care.
ARE THE EFFECTS PERMANENT?
Some effects of hormone therapy are permanent, and some are not, which is a central part of the careful decision-making before starting.
As Mayo Clinic notes, some of the changes brought on by gender-affirming hormone therapy cannot be reversed. With testosterone, for example, voice deepening and facial hair growth are generally lasting, while other changes largely reverse if the hormone is stopped. With estrogen, breast development is generally lasting, while many other changes reverse.
Because of this mix, the therapy is discussed thoroughly beforehand.
Hormone therapy can also affect fertility, which is why fertility is discussed before starting; see puberty blockers and fertility for more on that conversation.
HOW HORMONE THERAPY IS MONITORED
Hormone therapy is overseen with regular check-ins and blood tests, so effects can be tracked and managed.
Care teams monitor hormone levels and general health, and watch for specific effects, such as a rise in red blood cell count with testosterone or a small increase in blood-clot risk with estrogen, catching and managing them early.
For details, see our pages on testosterone side effects and the risks of gender-affirming hormones.
WHAT THE EVIDENCE SHOWS
Research associates gender-affirming hormone therapy with improved quality of life and reduced depression and anxiety, though much of that evidence comes from studies of adults and describes associations rather than proven causation.
A 2021 systematic review in the Journal of the Endocrine Society found that hormone therapy may be associated with improvements in quality-of-life scores and decreases in depression and anxiety symptoms among transgender people, and the 2023 Nature Human Behaviour review reported similar associations.
Both note that the evidence base is largely adult, still growing, and observational, so these are associations, and the researchers call for larger, longer studies.
Major US medical organizations, the American Medical Association, American Academy of Pediatrics, American Psychological Association, and Endocrine Society, regard this care as evidence-based and medically necessary. The genuine discussion about the certainty of long-term evidence is covered on our page on the risks of gender-affirming hormones.