Leuprorelin is a type of hormone therapy known as a LHRH (luteinising hormone-releasing hormone) agonist. It is used in the treatment of prostate cancer and breast cancer.

How it works

Prostate cancer

It lowers the level of testosterone made by the testicles. Prostate cancer depends on testosterone to grow. So leuprorelin can shrink cancer or slow its growth.

Breast cancer

It is sometimes used in the treatment of breast cancer. It is for women who have breast cancer that has oestrogen receptors (ER positive) and who have not yet gone through the menopause.

Leuprorelin lowers the level of oestrogen in the body by stopping the ovaries making oestrogen. This is because high levels of oestrogen can help the cancer to grow.  This injection can be given on it's own, or with other hormone therapies. 

How you have it

You have leuprorelin as an injection either:

• into a muscle in your leg or buttocks
• under the skin (subcutaneously) into fatty tissue in your tummy (abdomen), thigh or upper arm

The injection is called a depot injection. It means that you slowly absorb the drug into your body over a period of time. 

When you have it

You have leuprorelin as an injection once a month or every 3 months.

Tests

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 is working.

Side effects

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

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. For example, your side effects could be worse if you are also having other drugs or radiotherapy.

When to contact your team

Your doctor or nurse 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

Temporary side effects (prostate cancer)

If you are having leuprorelin to treat prostate cancer, you might have an increase in symptoms after your first dose of this drug. This may carry on for a few weeks. This is called tumour flare. So your doctor might give you another type of hormone drug to prevent the symptoms of tumour flare. 

Symptoms of tumour flare include:

• increased pain or difficulty passing urine
• bone pain
• back pain
• blood in your urine
• a feeling of pins and needles in your legs

Common side effects

These side effects happen in more than 10 out of 100 people (10%). You might have one or more of them. They include:

Skin reaction around the injection site

Reactions include redness, irritation, hardening or ulcers appearing around the injection site. Tell your nurse or contact your advice line if you notice any of these.

Tell your nurse if you notice any signs of redness or irritation around the injection site.

Loss of interest in sex

Talk to your doctor if you have this. You might be able to have some treatments to help with low libido. 

Hot flushes and sweating 

We have some tips for coping with hot flushes and the possible treatments for men and women. Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe you some medicines.

Tiredness and weakness (fatigue)

Tiredness and weakness (fatigue) can happen during and after treatment - doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Weight gain

You may gain weight while having this treatment. You may be able to control it with diet and exercise. Tell your doctor or nurse if you are finding it difficult to control your weight. 

Pain in muscles and joints 

You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Erection problems 

You might have problems getting an erection (impotence). Talk to your doctor or nurse if you have problems getting an erection. There are treatments that can help, such as medicines, vacuum pumps and injections or pellets. Your doctor or nurse can refer you to a specialist in this area.

Occasional side effects

These side effects happen in between 1 and 10 out of 100 people (1% to 10%). You might have one or more of them. They include:

• aching joints
• breast swelling
• swollen hands and feet
• headaches and dizziness
• changes in blood sugar levels
• depression
• loss of appetite
• difficulty sleeping (insomnia)
• liver changes
• feeling or being sick
• muscle weakness

Rare side effects

These side effects happen in fewer than 1 out of 100 people (1%). You might have one or more of them. They include:

• high temperature (fever)
• diarrhoea
• numbness or tingling in fingers or toes

Other side effects

There isn't enough information to work out how often these side effects might happen. You might have one or more of them. They include:

• blood clots in the lungs causing breathlessness and pain in the chest or upper back. Contact your advice line or doctor straight away as this can be life threatening
• bruising, bleeding gums or nosebleeds
• eyesight changes
• allergic reaction
• high temperature (fever) or chills
• increased risk of getting an infection
• heart problems
• bone thinning (osteoporosis)
• increased cholesterol in the blood
• lump at the injection site
• increased pain or difficulty passing urine

Coping with side effects

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

What else do I need to know?

Other medicines, food 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.

Pregnancy and contraception

This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you're having treatment.

Talk to your doctor or nurse about effective contraception before starting treatment. Women should use a non hormonal form of contraception. Your periods may stop during leuprorelin, but you could still get pregnant.

Breastfeeding
 

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

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.