BMA Concise Guide to Medicine & Drugs


Brand names Androcur, Cyprostat

Used in the following combined preparations Acnocin, Co-Cyprindiol, Dianette


Drug group Male sex hormone

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes


Cyproterone blocks the actions of male sex hormones (such as testosterone) and reduces the amount of them produced in the body. It is used in males to treat conditions that rely on androgens for their continuation, such as prostate cancer, hypersexuality, sexual deviation, and precocious puberty in boys. It is used in women to treat certain conditions due to abnormally high androgen levels, such as hirsutism, male-pattern baldness, and severe acne. For women who are taking cyproterone combined with an oestrogen for acne or hirsutism, the medication also provides contraception. Cyproterone alone is also used to facilitate hormonal male-to-female gender reassignment. Common side effects in men include reduced libido, erectile dysfunction (impotence), and infertility, which is usually reversible. Occasionally, cyproterone may disrupt liver function, and it significantly increases the risk of thrombosis.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets.

Frequency and timing of doses 1–3 x daily, with liquid after meals. Oral contraceptives Once daily on certain days of the menstrual cycle.

Adult dosage range 50–300mg daily, usually in divided doses. Oral contraceptives 2mg daily.

Onset of effect Up to a week; longer for acne, possibly several months.

Duration of action Several days.

Diet advice None.

Storage Keep at room temperature, away from heat, moisture, and direct light and out of the reach of children.

Missed dose Take as soon as you remember and take the next dose when it is due.

Stopping the drug Do not stop taking the drug without consulting your doctor; stopping the drug may lead to recurrence or worsening of your symptoms. If you have diabetes, stopping the drug may upset control of your blood sugar levels.


Cyproterone may cause a wide range of adverse effects, although serious ones are rare. In men, common side effects include decreased libido, erectile dysfunction (impotence), and infertility. In both sexes, the drug may cause restlessness, low mood, breast swelling or tenderness, hot flushes, sweating, dry skin and hair loss. If you develop persistent abdominal pain, abnormal itching, jaundice, breathlessness, chest pain, or swollen or painful calves, you should stop taking the drug and contact your doctor immediately. Long-term use of high doses of cyproterone has also been associated with certain tumours and alteration of liver and adrenal gland function (see Prolonged use).


Thiazolidinedione antidiabetic drugs (e.g. pioglitazone) The dose may need to be reduced when taken with cyproterone.

Rifampicin, phenytoin, and St John’s wort may reduce the level of cyproterone.

Ketoconazole, itraconazole, and clotrimazole may increase the level of cyproterone.

Statins may increase the risk of muscle side effects when taken with cyproterone.


Be sure to tell your doctor if:

· You have liver problems.

· You have diabetes.

· You have sickle cell anaemia.

· You have a history of depression.

· You have a family history of venous thrombosis or have had blood clots, stroke, or a heart attack.

· You have or have had a meningioma.

· You are taking other medicines.

Pregnancy Not prescribed. It can feminize a male fetus.

Breast-feeding Not prescribed.

Infants and children Reduced dose necessary.

Over 60 No special problems.

Driving and hazardous work Avoid such activities until you have learned how cyproterone affects you because the drug may cause tiredness and weakness.

Alcohol Avoid. Alcohol can reduce the effect of cyproterone.


The development of meningiomas (a type of brain tumour), abnormal liver function, suppression of adrenal gland function, and very rarely, liver tumours have been reported with prolonged use of cyproterone at high doses. Meningiomas are not a risk with Co-Cyprindiol (Dianette).

Monitoring Your blood count and liver function will be checked regularly, and your adrenal function may also be monitored. If you have diabetes, your blood sugar control will be monitored.