Exemestane (Aromasin)

Everyone reacts differently to drugs and some people have more side effects than others. For most people any side effects usually improve within the first few months of starting the treatment. However, if you have persistent side effects, tell your specialist team so they can help you manage these.

Aching or pain in the joints and/or muscles

One of the most common side effects is aching or pain in the joints and/or muscles.

Symptoms can occasionally be severe but are often mild and temporary, and can usually be relieved by mild pain relief like paracetamol and/or an anti-inflammatory such as ibuprofen. Talk to your doctor before using anti-inflammatory pain relief for this.

Menopausal symptoms

You may have menopausal symptoms such as hot flushes, sweating, mood swings, reduced libido (sex drive) and vaginal dryness. Many people find these symptoms improve over time.

To find out more about coping with these side effects see our information on menopausal symptoms and sex and intimacy.

Low mood/depression

Some people may experience mood changes including feeling low or depressed. It can be difficult to know whether feeling like this is because of the medication or is due to other reasons such as menopausal symptoms or dealing with a diagnosis of cancer. 

You can talk to your GP (local doctor) or specialist about how to manage a change in mood.  

Find out more about low mood and depression.

Difficulty sleeping

If you have difficulty sleeping (insomnia) you may benefit from simple, practical measures such as limiting caffeine, keeping your room dark and quiet and going to bed and getting up at the same time each day. Relaxation exercises can also be helpful. There are CDs, podcasts and phone apps that can guide you through these techniques. If your insomnia is persistent, your GP may prescribe something to help you sleep.


Fatigue (extreme tiredness) is a commonly reported side effect. Studies show that physical activity can help to relieve fatigue. For more information about the benefits of physical activity during and after breast cancer treatment you can speak to your breast care nurse or call our free Helpline.

Some people report feeling sleepy, although this is less common.

Complementary therapies are helpful for some people.

If you are being treated for secondary breast cancer, you may want to see our tips on secondary breast cancer and managing fatigue or you can get further information in our Secondary breast cancer resource pack.

Osteoporosis (thinning of the bone)

Exemestane reduces the amount of oestrogen in the body and lack of oestrogen over time can cause osteoporosis. Because of this, your specialist will usually check your bone density (strength and thickness) with a scan before or shortly after you start taking exemestane.

Your bone density may also need to be checked around every two years with a repeat scan while you are taking exemestane.

Last reviewed: June 2016
Next planned review begins 2018

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