Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

Megestrol acetate (Megace)

This page tells you about megestrol acetate (Megace) and its possible side effects. There is information about


What megestrol acetate is

Megestrol acetate is a type of hormone treatment. It is also called Megace or megestrol. It is a man made version of the hormone progesterone. Progesterone is one of the female sex hormones but men also produce a small amount of it.

Megestrol acetate is a treatment for the following cancers which have come back after treatment or have spread from where they started.

Megestrol is also a treatment for poor appetite and your doctor may suggest that you take it if you have lost weight because of cancer or its treatment.

Doctors may also suggest it as a treatment for hot flushes in women due to cancer or its treatment.

Megestrol can interfere with the hormone balance in the body so that the body makes smaller amounts of the hormones that some cancers depend on to grow. It may also interact with other hormones or have a direct effect on the cancer to stop it growing.


How you have megestrol

Megestrol is a tablet. You usually take it once a day but sometimes the dose is divided up so that you take it a couple of times a day. Swallow the tablet with a glass of water. Your doctor will tell you how often and when you should take it.

It is very important that you take tablets according to the instructions your doctor or pharmacist gives you. For example, whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

The side effects associated with Megestrol are listed below. To find out about coping with the side effects you can click on the underlined links. Where there is no link you can find information in our cancer drugs side effects section.


Common side effects

More than 10 in every 100 people have one or more of these. Remember you may only have one or two of these effects and they may be mild.

  • Increase in your appetite – some people take megestrol to help increase their appetite
  • Feeling and being sick especially when you first start taking it
  • Fluid retention causing ankle and finger swelling
  • Weight gain from increased appetite and food intake – watching what you eat and exercising regularly can help control your weight
  • Vaginal bleeding, which is not part of your period (spotting), or your periods may stop

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.


Rare side effects

Fewer than 1 in 100 people have these.

  • An allergic reaction – let your doctor or nurse know straight away if you have sudden swelling of the face, lips, or tongue, a skin rash, or difficulty breathing
  • Blood clots – contact your doctor or nurse straight away if you suddenly become breathless or if you have pain, tenderness or swelling in your leg, or your leg feels hot and becomes red
  • Hair thinning
  • Heart changes which can slightly increase your risk of a heart attack – your doctor will check your heart regularly while you are having this  treatment
  • Carpel tunnel syndrome – let your doctor or nurse know if you have any pain, tingling or weakness in your hands

Important points to remember

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

  • How many times you've had the drug before
  • Your general health
  • The amount of the drug you have (the dose)
  • Other drugs you are having

Talk to your doctor, pharmacist or nurse about all your side effects so that they can help you manage them. They can give you advice or reassure you. Your nurse will give you a number to call if you have any questions or concerns. If in doubt, call them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies – some drugs can react together.

Megestrol can harm a developing baby. Talk to your doctor or nurse about contraception before having treatment if there is any chance you or your partner could become pregnant.

Megestrol may be present in breast milk so do not breast feed during treatment or for 2 months after the last dose.


More information about Megace

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

Rate this page:
Submit rating


Rated 5 out of 5 based on 2 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 18 March 2013