Testosterone in gender affirmation
For trans men, transmasculine people and some non-binary people, testosterone helps physical characteristics align with identity: a deeper voice, facial hair and more defined muscles.[1],[2]
Changes vary greatly between individuals, depending on genetics, age and response. One point many people do not know: testosterone is not contraception. Pregnancy remains possible even after periods stop.[1],[3]
Why accurate information matters
Accurate information sets realistic goals, reduces disappointment and prevents unplanned pregnancy.[1] Many people raise their dose to speed up changes, but higher doses do not reliably work faster and they increase the risk of thick blood, acne and other side effects.
Needs differ between people
Using gender-affirming hormones is not a measure of mental illness. The World Health Organization classifies gender incongruence under sexual health, not mental disorders.[4] Care needs differ with goals and access; some people want full physical change, others only some changes.
Expected changes
Testosterone causes several changes that begin at different times.[1],[2]
- In the first few months: oilier skin and possible acne, increased libido, clitoral growth, and periods usually stopping within a few months.
- Over months to a year: the voice starts to deepen, body and facial hair increase, muscle mass grows and fat redistributes in a masculine pattern.
- Usually permanent changes: a deeper voice, facial and body hair, clitoral growth, and male-pattern hair loss in those predisposed, even if testosterone stops.
- Reversible changes: fat and muscle distribution; periods may return when testosterone stops.
Most changes take several years to reach their full effect.
What is assessed and monitored
Before starting, your doctor reviews your goals, medical conditions, haematocrit, blood pressure and the possibility of pregnancy.[1],[2]
During treatment, monitoring includes testosterone levels timed to the formulation, haematocrit, blood pressure and symptoms. The Endocrine Society recommends keeping levels within the typical male range, with more frequent checks in the first year.[2] A rising haematocrit is the side effect to watch most closely.
Using testosterone safely
Choose the formulation with your doctor. Testosterone comes as injections or gel, each with trade-offs. Blood tests must be timed to the formulation, and haematocrit, blood pressure and symptoms reviewed regularly.[1],[2]
Prevent pregnancy. If you have a uterus and ovaries, pregnancy can occur without periods, and testosterone can harm a developing baby. If you have sex that could lead to pregnancy, discuss suitable contraception with your doctor.[1],[3]
Plan for fertility. If you may want biological children, talk to your doctor before starting. Do not stop or adjust treatment yourself in order to conceive.[1],[2]
How we care for you at Dr. Kris Clinic
We care for trans men and transmasculine people with respect, using your chosen name and pronouns, in English or Thai. We explain realistic changes and timeframes, choose the formulation together and follow you up regularly.
We discuss contraception and the screening you still need, such as cervical screening, in a natural and comfortable way, because good health care follows the organs you have, not the sex on your documents.
Frequently asked questions
My periods stopped on testosterone. Can I still get pregnant?
Yes, if you have a uterus and ovaries. Testosterone is not contraception; use suitable contraception.
When will my voice deepen?
It usually starts changing in the first months and settles over about one to two years. Once deepened, it is usually permanent.
Can I take more to grow a beard faster?
No. Higher doses do not reliably speed changes and raise the risk of thick blood and acne.
Do I still need cervical screening?
If you still have a cervix, you should have screening as recommended for everyone.
Testosterone helps physical characteristics match your goals, but changes vary between people.[1] Keep up regular monitoring, never raise the dose to speed things up, and remember that testosterone is not contraception.
Talk to a doctor about this
Confidential care in Surat Thani, the mainland gateway to Koh Samui, Koh Phangan and Koh Tao. Tue–Fri 17:00–20:00 · Sat–Sun 10:00–15:00 (UTC+7)
Book a visit LINE @dr.krisclinic WhatsAppYour appointment is confirmed once the booking system or the clinic confirms it.
Dr. Krida Uakridathikarn (Dr. Kris)
Board-certified family physician with certificate training in clinical sexology and sexual medicine. He works at Suratthani Hospital and provides sexual health, hormone and LGBTQ+ inclusive care at Dr. Kris Clinic. Profile and CV
References
- WPATH Standards of Care, Version 8 (2022)
- Endocrine Society: Gender Dysphoria/Gender Incongruence (2017)
- CDC U.S. SPR 2024: Testosterone Use and Risk for Pregnancy
- WHO: Gender incongruence and transgender health in ICD-11
Keep reading
Main guide: Gender-affirming care
Preparing for Gender-Affirming Hormone Therapy (GAHT)
Hormones for Trans Women and Transfeminine People: Safe Regimens and What to Expect
Oral, Transdermal and Injectable Estrogen: How They Differ and Which Is SaferThis article is general education, not personal medical advice or a promise of results. Diagnosis and treatment require assessment by a doctor. Content reflects the cited sources as of the update date.