Masculinising Hormone Therapy (FTM): Starting Testosterone Safely

Many trans men have told me that the first day they heard their voice drop, or saw their first facial hair, was the day they felt "This is me." Testosterone is very powerful in helping the body align with identity, but power has to be used with understanding, because some changes are permanent, and some important things are often forgotten, such as contraception.

What does testosterone do in the body?

Masculinising hormone therapy uses testosterone to bring on male characteristics and suppress the ovaries, so periods stop. Most people don't need an additional medicine to suppress female hormones.

It suits trans men and non-binary people who want masculine changes. Some choose a lower dose for partial changes only (see non-binary).

Forms of testosterone used in Thailand

Doses must be set by a doctor based on blood results. For comparisons of injection versus gel, and of the two injectables, see testosterone injections vs gel and Test E vs Test U.

Approximate timeline of changes

Based on the Endocrine Society guideline (2017). These are averages and vary between people.

A deeper voice, facial hair and clitoral growth usually remain permanently even after stopping, so make sure you understand this with your doctor before you start.

1. 1-6 months
   Periods stop, oily skin, acne

   Clitoral growth, vaginal dryness and thinning, fat starts to redistribute male-pattern

2. 6-12 months
   Voice deepens, facial hair begins

   Muscle and strength increase; hair may thin if genetically prone

3. 1-2 years
   Voice, acne, clitoris settle

   Most early changes reach their full extent

4. 2-5 years
   Body shape and muscle full

   Male fat distribution fully established

5. 4-5 years
   Beard and body hair full

   Hair grows slowest; be patient

Averages from Endocrine Society (2017). Voice, facial hair and clitoral enlargement are usually permanent.

Blood targets and monitoring

• Testosterone is targeted within the typical male range. For weekly or fortnightly injections, it is usually measured at the midpoint between doses.
• Haematocrit (blood concentration) is checked, because testosterone stimulates red blood cell production.
• Lipids, glucose, liver values, blood pressure and weight are checked.
• In the first year, follow-up is about every 3 months, then every 6–12 months.

See the list of tests in blood tests before starting gender-affirming hormones, and side effects to manage in testosterone side effects in trans men.

Important things that are often forgotten

1. Testosterone is not contraception. Even when periods stop, you can still ovulate and become pregnant. If you have sex that could lead to pregnancy, use another method of contraception, such as condoms, an IUD or progestin-only contraception, which can be used together with testosterone. Testosterone is harmful to a developing fetus.
2. Cervical screening is still needed if you still have a cervix. In some places HPV testing can be self-collected, which reduces discomfort.
3. Breast care. Even after chest surgery, some breast tissue may remain, so watch for unusual lumps.
4. Fertility. If you may want genetic children in the future, talk about egg freezing before starting.
5. STI and HIV prevention. Thinner vaginal tissue can tear more easily; use lubricant and consider PrEP according to your risk.

Contraception

• Testosterone is not a contraceptive
• You can still get pregnant if periods stop

Cervical screening

• Still needed if you have a cervix
• HPV self-sampling in some places

Breast care

• Some tissue may remain after surgery
• Watch for abnormal lumps

Having children

• If you want genetic children later
• Discuss egg storage before starting

STI/HIV prevention

• Use lubricant
• Consider PrEP by risk

After removal of the uterus and ovaries

Without ovaries, your body makes no sex hormones of its own at all, so continuing testosterone is important for bones, muscle and mood. Read more in do trans men still need hormones after removal of the ovaries?

Signs you need a doctor urgently

• A severe headache or unusually flushed face together with very thick blood on testing
• Chest pain, breathlessness or swelling in one leg (call 1669, Thailand's medical emergency number)
• Vaginal bleeding returning after periods have stopped for a long time
• Severe mood swings or thoughts of harming yourself (call 1323, Thailand's free mental-health hotline; Thai language, ask for English support)

Understanding care at Dr. Kris Clinic

At Dr. Kris Clinic, I care for trans men's hormone therapy from the first consultation and blood tests to choosing a form of medicine, injections given by medical staff and long-term follow-up, including for people who have bought injections themselves and want to make things safer. Care is available at the clinic in Surat Thani and online, with English-speaking consultations. For the overview, read gender-affirming hormone therapy (GAHT).