Cyproterone acetate (Cyprostat)

Read about cyproterone acetate, how you have it and other important information about taking this hormone therapy. 

Cyproterone is a hormone therapy and is also known by its brand name Cyprostat. It is a type of drug called an anti androgen. 

It is a treatment for prostate cancer.

You take cyproterone acetate either on its own, or with another type of drug for prostate cancer called a luteinising hormone (LH) blocker. 

LH blockers include:

  • Goserelin (Zoladex)
  • Leuprorelin (Prostap)
  • Triptorelin (Decapeptyl SR, Gonapeptyl Depot)

You might have cyproterone acetate with a luteinising hormone blocker to stop what is called a flare reaction. When you first start taking LH blockers you actually make more testosterone for the first few days or weeks, which increases the symptoms of the prostate cancer. This soon settles down, and after a few weeks you stop making testosterone. Cyproterone acetate helps to reduce any cancer symptoms caused by this temporary increase in testosterone.

Cyproterone can also help to reduce hot flushes in men:

  • who have had their testicles removed as a treatment for prostate cancer
  • who are taking luteinising hormone (LH) blockers

How it works

Prostate cancer cells depend on the hormone testosterone in order to grow. Cyproterone lowers levels of testosterone in the body and also blocks testosterone from reaching the cancer cells. It slows or stops the growth of prostate cancer. 

How you have it

You take cyproterone acetate as a tablet 2 or 3 times a day, with water after meals. Try to take it at evenly spaced times during the day.

If you are having it to stop a flare reaction, you take it for a few days before starting the luteinising hormone blocker, and stay on it for about 4 to 6 weeks.

When you stop taking cyproterone you need to reduce the dose gradually. Your doctor will tell you exactly how to do this.

Taking your tablets or capsules

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

Whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, not more or less.

Talk to your specialist or advice line before you stop taking a cancer drug.


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Side effects

Important information

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.


Avoid drinking alcohol while having this treatment because alcohol reduces the effect of the drug.

Treatment for other conditions

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.

If you have diabetes

This drug may affect your blood sugar levels if you have diabetes. You need to check your blood sugar more often when you are having this treatment.


It is important not to father a child while you are having treatment with this drug and for a few months afterwards. This drug may harm a baby developing in the womb. Talk to your doctor or nurse about effective contraception before starting treatment. 

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

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