Oestrogen based GAHT (also called E-GAHT) consists of 2 types of medicines – a form of oestrogen and a medicine to block testosterone. Both are needed unless you've had surgical removal of your testicles (in which case a testosterone blocker isn't usually needed).
It can be used by trans women or non-binary people who were assigned male at birth.
Effects of E-GAHT
E-GAHT can lead to gradual changes over many months and years. There are some things it can't change (see below). Effects vary between individuals.
|Effects of E-GAHT
- *Breast growth
- *Infertility (please discuss the option of storing sperm prior to starting E-GAHT)
- *Shrinking of your testicles
- Lower sex drive
- Decreased erections
- Skin softening
- Body fat redistribution
- Reduced muscle mass
- Slower hair growth on body and face (but it doesn't stop completely)
*Breast growth, likely infertility and genital changes are permanent (they may not reverse if you stop taking E-GAHT)
E-GAHT does NOT change the following:
- voice (your healthcare provider may be able to refer you for voice therapy)
- bone structure
- adams apple
- hair growth does not stop completely (some people use laser hair removal).
Note: contraception should still be used if you're having sex which could result in pregnancy.
You may hear about people using progesterone as part of E-GAHT, but currently there's not enough evidence for the benefit of using this as part of GAHT, so it's not generally recommended.
Oestrogen is usually started at a low dose and gradually increased over the first year of therapy. There are 2 forms of oestrogen funded and available in Aotearoa New Zealand:
- Tablets (Progynova)
- Patches (eg, Estradot). Oestrogen patches have a lower risk of blood clots than tablets.
Oestrogen injections are not funded in Aotearoa New Zealand. There's no evidence that oestrogen injections are more effective than the tablets or patches, and they may carry more risk because they can lead to higher oestrogen levels. For this reason, they're not part of national medical guidelines.
Oestrogen can cause blood clots (unless you use patches), liver problems, raised cholesterol and breast cancer. Risks are higher if you smoke, are over 45 years of age or have a family history of certain health problems.
In Aotearoa New Zealand spironolactone tablets or cyproterone tablets are commonly used. Some people may use an injected implant (goserelin).
- Spironolactone works by blocking the effects of testosterone in the body, eg, by promoting breast growth and slowing down body hair. Spironolactone can change blood potassium levels so blood test monitoring is important especially if you have kidney problems. Read more about spironolactone.
- Cyproterone works by stopping the release of testosterone. Cyproterone can cause side effects including low mood, weight changes, problems with your liver and meningioma (a non-cancerous brain tumour), so you should discuss this with a medical professional and use the lowest effective dose. Read more about cyproterone.