Gender-affirming hormone therapy (GAHT) is a treatment in which people take hormones such as estrogen or testosterone, or hormone blockers, that help achieve physical characteristics that are more masculine or feminine. Hormone therapy for transgender and gender-fluid people can improve mental well-being and quality of life by more closely aligning someone’s outer appearance with their gender identity.
GAHT uses medicine to replace or suppress the hormones your body makes, typically estrogen and testosterone, that influence your outward appearance after puberty. During puberty, your body increases production of hormones that cause either feminine or masculine characteristics to become more pronounced. These include a lowered voice, body hair, increased muscle mass or breast growth.
If your body has gone through puberty but you haven’t had genital surgery, taking GAHT can suppress some physical traits created by your body’s hormones. If you have had genital surgery, taking GAHT replaces hormones that your body no longer makes, which is important for bone health.
Prescribed by a primary care provider or endocrinologist, GAHT can be part of a presurgical plan or a stand-alone service for adult patients.
Who may be a candidate for gender-affirming hormone therapy?
Hormone therapy may be part of a transition for gender-fluid individuals. It may be used in conjunction with transgender surgical procedures, but these procedures are not a requirement for receiving GAHT.
Patients interested in hormone therapy for gender affirmation must meet the following criteria:
- Have a diagnosis of gender dysphoria or incongruence from an experienced health professional
- Be able to make an informed decision and consent to treatment
- Have a thorough discussion about medical history, including mental health history, with your doctor and receive a physical exam to identify any conditions that could affect your GAHT treatment
How Hormones Are Given
Hormones can be taken as tablets, applied through the skin as patches, gels, or creams, or given by injection. Which route suits you depends on your preference, how well it works for you, and the side-effect profile.
Treatment normally starts at a low dose and increases gradually. This achieves the intended effects while keeping risks manageable, and it gives time to see how your body responds. Following the prescribed dose and attending monitoring appointments matters more here than in most treatments, because both under- and over-dosing carry consequences.
Feminizing Hormone Therapy (MtF)
Estrogen develops feminine characteristics, such as breast growth, softer skin and fat redistribution. It’s available as tablets, patches, gels or injections. Ethinyl estradiol, the type found in many contraceptive pills, is avoided because it carries a higher risk of blood clots. Your doctor will choose the safest form for you.
Anti-androgen medication suppresses testosterone, and several options are used:
- Spironolactone blocks testosterone activity and requires monitoring of blood pressure and electrolytes.
- Cyproterone acetate is effective, with liver function requiring monitoring.
- GnRH agonists suppress testosterone production directly. They are effective but more expensive, and usually given by injection.
- 5-alpha-reductase inhibitors can help with scalp hair and skin, and are sometimes used alongside the above.
Masculinizing Hormone Therapy (FtM)
Testosterone can be taken orally, applied through the skin, or given by injection. The aim is the lowest dose that achieves the intended effects, which also helps preserve bone density over the long term.
Physical Effects of Hormone Therapy
Masculinising therapy brings a deeper voice, increased body and facial hair, growth of the clitoris, cessation of periods, reduced breast tissue, increased muscle mass, and redistribution of body fat.
Feminising therapy brings breast development, softer skin, reduced body hair, reduced erectile function, decreased testicular size, redistribution of body fat, and reduced muscle mass.
Changes develop gradually over roughly two to three years, and the extent varies considerably between individuals. Some effects are permanent even if treatment stops — voice deepening and facial hair from testosterone, and breast growth from oestrogen. Others reverse. Knowing which is which before starting matters, and we go through it in detail at consultation.
Hormone therapy does not change some characteristics at all. Facial bone structure, height, and an established Adam’s apple are unaffected, which is why many patients also consider facial feminisation surgery, facial masculinisation surgery, tracheal shave, or voice surgery.
Expected Changes and Timeline
Changes happen gradually and vary between people. The figures below are approximate.
Feminizing therapy
| Change | Starts | Maximum effect |
|---|---|---|
| Softer skin | 3–6 months | Varies |
| Reduced erections and libido | 1–3 months | 3–6 months |
| Breast growth | 3–6 months | 2–3 years |
| Fat redistribution | 3–6 months | 2–5 years |
| Reduced muscle mass | 3–6 months | 1–2 years |
| Smaller testicles | 3–6 months | 2–3 years |
Estrogen does not change the voice. See Voice Feminization Surgery.
Masculinizing therapy
| Change | Starts | Maximum effect |
|---|---|---|
| Periods stop | 2–6 months | — |
| Deeper voice | 3–12 months | 1–2 years |
| Clitoral enlargement | 3–6 months | 1–2 years |
| Facial and body hair | 3–6 months | 3–5 years |
| Increased muscle mass | 6–12 months | 2–5 years |
| Reduced breast tissue | Slight | — |
Testosterone doesn’t remove breast tissue. See Top Surgery.
Fertility
Both feminising and masculinising hormone therapy can reduce fertility, in some cases permanently. Anyone who may want biological children later should discuss fertility preservation before starting treatment, since options narrow considerably once therapy has begun. This conversation is part of our consultation rather than an afterthought.
Health Monitoring
Regular monitoring is what makes long-term hormone therapy safe. It typically includes blood tests to check hormone levels, liver function, lipid profile, blood count, and other parameters relevant to your treatment, along with checks on blood pressure and cardiovascular risk factors.
Monitoring also picks up side effects early, while they are still easy to address. Long-term care includes age-appropriate screening — see Preventive Healthcare for Transgender Patients — which needs tailoring, since screening requirements depend on which organs a person has rather than on their gender marker.
Hormone therapy is individual. Dose, preparation, and monitoring should reflect your medical history, risk factors, and goals, and the plan works best when built together with your doctor rather than handed to you.
Risks of Gender-Affirming Hormone Therapy
Untreated gender dysphoria carries serious risks of its own, and that context matters when weighing the risks of treatment. But hormone therapy does carry real risks, and they deserve straight discussion rather than reassurance.
Depending on your age and any pre-existing conditions, hormone therapy can increase the risk of cardiovascular events, including heart attack, stroke, and blood clots, including pulmonary embolism. Oestrogen carries a particular association with clotting risk; testosterone affects lipid profile and red blood cell count. Liver function needs monitoring on certain medications. Smoking substantially compounds the cardiovascular risk, which is why we raise it directly.
*Take only hormones prescribed to you by a doctor*
Self-sourced hormones — bought online, shared, or obtained without a prescription — are a genuine danger, because nobody is checking your dose, your blood results, or your clotting risk. This is one of the more common ways transgender people come to serious harm, and it is entirely preventable.
Why Choose Kamol Hospital for Hormone Therapy?
Two things separate good hormone care from the alternative, and neither is the prescription itself.
The first is monitoring. Writing a first prescription is straightforward; managing hormone therapy safely across years — adjusting doses against blood results, watching lipids and liver function, catching a rising clotting risk before it becomes an event — is the actual work. As a licensed hospital, we have laboratory services, endocrinology, and cardiovascular assessment on site, so monitoring happens properly rather than being left to the patient to arrange.
The second is continuity across the whole transition. Many patients come to us for hormone therapy and later for surgery, or arrive for surgery already on hormones started elsewhere. Having both under one roof means the surgical team knows exactly what a patient is taking and can plan the pause and restart around the operation — which matters, because oestrogen and surgery interact through clotting risk. Fragmented care is where that gets missed.
Kamol Hospital has provided transgender healthcare for decades, and hormone therapy sits alongside gender reassignment surgery, phalloplasty, facial surgery, mental health support, and preventive care rather than being offered in isolation. Staff here treat transgender patients daily, which for many people is the difference between an appointment they dread and one they don’t.
We are also honest about what hormones will and will not do. Managing expectations about timelines, about which changes are permanent, and about what still needs surgery is part of good care — and it is better said at the first consultation than discovered two years in.
Kamol Hospital is accredited by the Joint Commission International. Our international patient team arranges scheduling, accommodation, and interpretation, and we can coordinate with your doctor at home where treatment continues there.
Frequently Asked Questions (FAQs)
Do I need surgery to start hormone therapy?
No. Surgery isn’t required to start GAHT. Many people take hormones without surgery, while others combine hormones with procedures such as SRS, FFS or top surgery.
How long does it take to see changes?
Some changes begin within a few months, but most develop gradually over 1–5 years. Everyone responds differently, and higher doses don’t speed up changes but do increase risks.
Are the changes reversible?
Some changes, such as fat redistribution and softer skin, may reverse if hormones are stopped. Others, such as breast growth, a deeper voice and facial hair, are usually permanent.
Will hormone therapy affect my fertility?
It can, and the effect may be permanent. If you may want biological children, discuss sperm or egg freezing before starting.
Do I need to stop hormones before surgery?
Some patients need to pause estrogen for a few weeks before surgery to reduce the risk of blood clots. Your surgeon will give you specific instructions.
I'm already on hormones from another doctor. Can Kamol continue my care?
Yes. Bring your prescriptions and recent blood tests, and our doctors will review your current treatment
Why shouldn't I buy hormones without a prescription?
Unprescribed hormones may be the wrong type or dose, and without monitoring, serious risks such as blood clots or liver problems can go unnoticed. Working with a doctor makes treatment safer and more effective.
Does Thailand have good doctors for transgender hormone therapy?
Thailand has provided transgender healthcare longer than most countries and has genuine depth in it, with endocrinologists and physicians experienced in GAHT and a healthcare culture in which transgender patients are treated routinely rather than as unusual cases. As anywhere, look for a licensed facility with proper laboratory monitoring rather than a clinic that will simply write a prescription.
Is it worth travelling to Bangkok, Thailand for hormone therapy?
For hormone therapy alone, a dedicated trip is rarely the practical choice, since GAHT needs regular blood monitoring and dose adjustment that is easier with a doctor near home. Where travelling makes real sense is starting treatment while you are in Bangkok, Thailand, for surgery or an assessment, or coming for a comprehensive review if care at home has been difficult to access — the cost of full hormonal and metabolic testing here is a fraction of what it is in Australia, the UK, or North America. We can then coordinate with your local doctor for ongoing prescriptions.
