Buserelin (Suprefact)

Buserelin is a hormone therapy drug and is also known by its brand name, Suprefact or Suprecur. 

It is a treatment for prostate cancer. 

How it works

Buserelin is a type of hormone therapy known as a LH (luteinising hormone) blocker. It stops the pituitary gland releasing luteinising hormone. This stops the testicles producing testosterone.

Prostate cancer depends on testosterone to grow. So buserelin can shrink the cancer or slow its growth. 

How you have it

You have buserelin as an injection under the skin. After several injections you have it as a nasal spray. 

You usually have injections under the skin (subcutaneous injection) into the stomach, thigh or top of your arm.

You might have stinging or a dull ache for a short time after this type of injection but they don't usually hurt much. The skin in the area may go red and itchy for a while.

The video below shows you how to give an injection just under your skin (subcutaneously). 

When you have it

You have it as an injection 3 times a day for 7 days. On the 8th day you start using buserelin as a nasal spray.

You spray the drug into each nostril 6 times a day. One way of remembering to do this is to use the spray before and after each meal. So you can have the treatment before and after breakfast, lunch and your evening meal. 

You continue taking the buserelin for as long as it is working. 

Tests during treatment

You have blood tests before starting treatment and during your treatment. They check your levels of testosterone every 3 months. They also check the levels of blood cells and other substances in the blood. Other tests see how well your liver and kidneys are working.

Side effects

How often and how severe the side effects are can vary from person to person. They also depend on what other treatment you are having. 

When to contact your team

Your doctor, nurse, or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects 
  • your side effects aren’t getting any better
  • your side effects are getting worse
Early treatment can help manage side effects better.

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

Side effects

Possible side effects include:

  • tummy (abdominal) pain
  • joint or muscle pain
  • bowel changes
  • swollen hands and feet (fluid build up)
  • hot flushes
  • fast heart rate
  • feeling or being sick
  • skin rash
  • loss of interest in sex
  • breast swelling (gynaecomastia)
  • weight gain or weight loss
  • blood pressure changes
  • tiredness and weakness (fatigue)
  • shrinking testicles (atrophy)
  • mood changes (such as depression or anxiety)
  • bruising at injection site
  • headaches and drowsiness
  • bone thinning which can increase your risk of bone fractures
  • hair thinning or thickening
  • numbness or tingling in hands or feet
  • difficulty sleeping (insomnia)
  • liver changes
  • splitting nails
  • dry eyes
  • feeling thirsty
  • appetite changes
  • problems with memory or concentration
  • eyesight changes
  • ringing in the ears (tinnitus)
  • second cancers
  • allergic reaction
  • increased risk of getting an infection
  • bruising, bleeding gums or nosebleeds
  • changes in blood sugar levels

Coping with side effects

We have more information about side effects and tips on how to cope with them.

At the start of treatment

When you start treatment with buserelin, testosterone can temporarily rise, before it drops to low levels. This is called tumour flare. 

This might cause temporary worsening of side effects such as bone pain or weakness.

What else do I need to know?

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.

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.


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. 


Don’t breastfeed during this treatment because the drug may come through into your breast milk.

Other medical conditions

If you have diabetes, high blood pressure or depression, tell your doctor. All of these conditions can be affected by buserelin 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.

This page is due for review. We will update this as soon as possible.

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