Side effects of hormone therapy in men

Different hormone therapy drugs cause different side effects. 

This page tells you about some of the side effects that hormone therapy may cause. Your healthcare team will tell you about specific side effects of your own treatment. 

It’s important to remember that you probably won't get every side effect listed, everyone is different. 


You may feel more tired when you are taking hormone therapy.

Sex and erection problems

Hormone therapy lowers the amount of testosterone in the body and this might affect: 

  • your ability to get and maintain an erection (erectile dysfunction)
  • your interest in having sex (libido)

This may get better within 3 to 12 months after the treatment ends.

For some men, erection problems are permanent. It depends on what drug you are having and how long you have been taking it.

Your healthcare team will be able to offer you advice.

Hot flushes and sweating

Hot flushes and sweating can be troublesome. How often you have them and how long they last will vary from person to person.

Lowered testosterone levels cause hot flushes.  They are most likely to happen when taking LHRH agonists (LH blockers) Open a glossary item, because these drugs stop testosterone production altogether.

Getting overheated, drinking tea or coffee, and smoking can all make flushes worse.

They may gradually get better as you get used to the treatment. But, in some men the flushes keep on happening as long as you take the drug.

Talk to your doctor or clinical nurse specialist if you have problems coping with hot flushes and sweating. There are treatments that may help.

Breast tenderness and swelling (gynaecomastia)

Hormone therapy changes the balance of hormones in your body. This can cause breast tissue to grow. This is called gynaecomastia.

Swelling can happen in either one or both breasts. It may be painful. It starts as fatty tissue. But it can develop into thicker (dense) tissue. 

You might have a hormone therapy called tamoxifen to help with this. Or you might have a small dose of radiotherapy before treatment starts. 

Pain from tumour flare

Pain caused by a secondary prostate cancer can temporarily worsen when you start hormone treatment. This is called tumour flare.

Your doctor should always prescribe another hormone therapy when you start a luteinising hormone blocker. This other hormone therapy helps to prevent tumour flare from causing bone pain. If the pain carries on, your doctor can prescribe drugs called bisphosphonates to treat it.

Weight gain

You might put on weight. You should be able to control this with diet and exercise. But it is often difficult to keep your weight down when you are having hormone treatment. Ask to see a dietitian for advice about managing your weight.

Memory problems

Some people feel that their memory gets worse when they are having hormone therapy and for a while afterwards. There are ways to make life easier, such as making lists so you don't forget things.

Talk to your healthcare team if you feel memory problems are having a significant effect on your life.

Mood changes and depression

Some people have mood changes or feel depressed while having hormone therapy. Talking with someone close to you may help. If you don't feel comfortable sharing your feelings with people you know, seeing a counsellor may help.

Bone changes

Men taking hormone therapy for prostate cancer are at risk of bone thinning (osteoporosis). How much bone thinning you might have varies from person to person. Not all hormone treatments cause bone loss.

Your doctor may suggest taking vitamin D and calcium to help lower your risk of problems from osteoporosis.

It might help to:

  • stop smoking
  • only drink alcohol within recommended limits
  • take regular weight bearing exercise, such as walking

Heart problems and diabetes

Hormone therapy for prostate cancer might increase the risk of heart problems and diabetes. This may partly be because lower testosterone levels can increase the amount of fats (cholesterol) and sugar (glucose) in your blood.

Remember that the side effects we have listed above are general ones. Tell your doctor or nurse if you have any side effects. They may be able to help reduce them.

  • Electronic Medicines Compendium 

    Accessed January 2024

  • British National Formulary 

    Accessed January 2024

  • Prostate cancer: diagnosis and management
    National Institute for Health and Care Excellence, 2019 (updated December 2021)

  • Prostate cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up
    C Parker and others
    Annals of Oncology, 2020. Volume 31. Pages 1119-1134

  • Side effects of androgen deprivation therapy
    Accessed January 2024

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact with details of the particular issue you are interested in.

Last reviewed: 
06 Feb 2024
Next review due: 
05 Feb 2027

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