Cancer drugs A to Z list
Leuprorelin is a type of . You pronounce leuprorelin as loo-pro-rehl-lin. It is also known as Prostap.
It is a treatment for breast cancer in women who haven’t gone through the .
Leuprorelin is also a treatment for prostate cancer.
Some men with breast cancer might have leuprorelin. To get information on the possible side effects for men, go to the leuprorelin for prostate cancer page.
Go to our information about leuprorelin for prostate cancer
Leuprorelin is known as a GnRH (gonadotropin-releasing hormone) agonist. It lowers the level of in the body by stopping the ovaries making oestrogen. This is because high levels of oestrogen can help breast cancer to grow.
You may have leuprorelin if the cancer has oestrogen receptors (ER positive) and you haven’t gone through the menopause.
You have leuprorelin as an injection under the skin (subcutaneously). This injection usually goes 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.
You can have leuprorelin either once:
a month
every 3 months
Contact your healthcare team if you miss an injection. Missing an injection can cause bleeding from your vagina and there is a chance you could become pregnant.
You may have this injection at your GP surgery or at the hospital.
You have blood tests before and during your treatment. They check your levels of and other substances in the blood. They also check how well your liver and kidneys are working.
Lowering sex hormone levels can also affect your bone strength over time. Your doctor may want you to have a bone density test (called a DEXA scan) before you start treatment, especially if you're at risk of .
Side effects can vary from person to person. They also depend on what other treatment you are having.
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
We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.
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.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
You may have hot flushes and sweat a lot. We have some tips for coping with hot flushes in women. We also explain some of the possible treatments. Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe you some medicines or suggest supportive therapies or lifestyle changes that may help.
You might experience pain in your bones. Speak to your doctor as they can prescribe medicine to help.
Let your doctor or nurse know if you have headaches. They can give you painkillers such as paracetamol to help.
Headaches with leuprorelin can be severe.
If you have difficulty sleeping, it can help to change a few things about how you try to sleep. Try to go to bed and get up at the same time each day and spend some time relaxing before you go to bed. Some light exercise each day may also help.
These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:
weight changes
depression
dizziness
feeling sick
tingling of the skin (paraesthesia)
mood changes - the longer you have leuprorelin the more common these mood changes become
muscle weakness or pain
joint pain
smaller breasts
tenderness in breasts
vaginal dryness
swollen hands and feet
skin reaction around the injection site - which may include changes in skin colour such as darkening or redness, irritation, hardening or ulcers appearing around the injection site
These side effects happen in fewer than 1 in 100 people (less than 1%). You might have one or more of them. They include:
loss of appetite
changes to the level of fats (lipids) in your blood
liver changes picked up on a blood test – this usually goes back to normal after treatment
a build up of fat in your liver
vision changes
a fast heartbeat
diarrhoea
being sick
hair loss
a high temperature
tiredness
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. Call 999 or go to accident and emergency (A&E) immediately if you have any of these symptoms as this can be life threatening
allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness - some allergic reactions can be life threatening, alert your nurse or doctor if notice any of these symptoms
a severe skin reaction caused by conditions such as toxic epidermal necrolysis (TEN) or Stevens Johnson syndrome (SJS) – symptoms include tender red patches on the skin, peeling or blistering of the skin, feeling feverish and eyes becoming more sensitive to light. Other skin reactions include having red spots or patches on the skin that have a dark red centre and paler red rings around them
breathless and looking pale due to a drop in (anaemia)
a drop in blood cells causing bruising, bleeding gums, nosebleeds or an increased risk of infection
metabolic syndrome –symptoms include high blood pressure, high cholesterol and high blood sugar levels which can increase the risk of heart disease and type 2 diabetes
seizures (fits)
increased pressure around the brain - symptoms include headache, double vision or other visual symptoms and ringing or buzzing in one or both ears
muscles not working (paralysis)
high or low blood pressure
yellowing of the skin and eyes (jaundice) caused by the liver not working well
bone thinning (osteoporosis) – including possible breaks (fractures) in the spine
inflammation and scarring of the lungs
vaginal and vulval problems such as inflammation, itchiness, soreness and feeling uncomfortable
heavy bleeding from the vagina
loss of interest in sex
We have more information about side effects and tips on how to cope with them.
Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.
Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.
This treatment might harm a baby developing in the womb. It is important not to become pregnant 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.
Let your healthcare team know straight away if you become pregnant while you're having treatment.
Don’t breastfeed during this treatment because the drug may come through into your breast milk.
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.
You can report any side effect you have to the Medicines and Healthcare products Regulatory Agency (MHRA) as part of their Yellow Card Scheme.
Last reviewed: 28 Mar 2026
Next review due: 28 Mar 2029
Treatment for breast cancer depends on a number of factors. Find out about breast cancer treatments, where and how you have them, and how to cope with possible side effects.
Cancer drugs have side effects and these can vary from person to person. But there are things that you can do to help you cope.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
Leuprorelin is a type of hormone therapy. It is a treatment for prostate cancer.
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