Cyproterone

Sounds like 'sye-pro-te-rone'

Key points about cyproterone

Cyproterone is used for many conditions, eg, prostate cancer and endometriosis. It's also used as gender affirming hormone therapy.
Cyproterone comes as tablets and is called Siterone.
It's also available in combination with oestrogen, as a combined oral contraceptive pill, eg, Ginet.
Find out how to take cyproterone safely and possible side effects.

Cyproterone is a type of hormone therapy. It's sometimes called a testosterone blocker because it stops the release of testosterone. Cyproterone has many uses including for:

endometriosis
prostate cancer, to slow or stop the growth of the tumour
gender affirming hormone therapy
head hair loss (alopecia) in people with a uterus.

Note: Cyproterone is also available in combination with oestrogen, in the combined oral contraceptive pill (eg, Ginet, Diane-35 and Estelle). It can be used for polycystic ovary syndrome for symptoms, eg, excess body hair or acne.

In Aotearoa New Zealand, cyproterone is available as tablets (50 mg and 100 mg).

The dose of cyproterone is different for different people, depending on its use.
Always take cyproterone exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it, and any special instructions.

Note: Cyproterone is also available in combination with oestrogen, in the combined oral contraceptive pill (eg, Ginet, Diane-35 and Estelle). Learn more about the combined oral contraceptive pill.

Swallow your tablets with a glass of water.
Take cyproterone with or just after food, or a meal.
Take cyproterone at the same time each day.
If you forget to take your dose, take it as soon as you remember. But if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.
Don't stop taking cyproterone suddenly, talk to your doctor before stopping.

Here are some things to know when you're taking cyproterone. Other things may be important as well, so ask your healthcare provider what you should know about.

Driving and operate machinery: Cyproterone may cause tiredness, so take special care with tasks, eg, driving or operating machinery. Be careful when driving or using tools until you know how this medicine affects you. Avoid or limit alcohol because it can make this worse.
Other medicines: Cyproterone may interact with other some other medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting cyproterone and before starting any new products.
Blood tests: You will need to have blood tests before starting cyproterone, and a few months later to check your liver and your blood glucose.
Pregnancy: Tell your doctor if you're pregnant or planning to become pregnant.
Depression: If you have a history of depression, let your doctor know.
Diabetes: If you have diabetes, let your doctor know.

Like all medicines, cyproterone can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects	What should I do?
Hot flushing, sweating Weight changes	Tell your doctor if they bother you.
Tiredness Impaired concentration	Be careful when driving or using tools until you know how this medicine affects you. Don't drink alcohol.
Mood changes	Tell your doctor if they bother you.
Less interest in sex, trouble getting or keeping an erection	Tell your doctor if they bother you.
Signs of blood clots, eg, swelling, pain or change in colour in one or both legs, chest pain, difficulty breathing or shortness of breath.	Let your doctor know immediately, or phone Healthline on 0800 611 116.
Signs of meningioma, eg, feeling confused, dizzy, having headaches or problems with your eyesight	Meningioma (a non-cancerous brain tumour) is rare. The risk is higher after prolonged exposure (several years) to high doses of cyproterone (25 mg a day and above). Let your doctor know immediately, or phone Healthline on 0800 611 116.
Signs of problems with your liver, eg, sudden pains in your stomach, loss of appetite or yellowing of your skin and eyes	Liver problems are rare but serious. Tell your doctor immediately or phone Healthline on 0800 611 116.