Medicines for diet problems

There are medicines that can help with weight loss, cachexia Open a glossary item and digestion problems.

Appetite stimulants

Appetite stimulants are for people who have lost a lot of weight or have cachexia and have a loss of appetite. They work for some people.

 Doctors can use the following hormone drugs:

  • megesterol acetate (Megace)
  • medroxyprogesterone acetate (Depo Provera and Provera)

Both drugs increase appetite and food intake. So, they can be helpful for people with cancer who have nutritional problems.

These drugs might also help you put on weight, but this can take up to 8 weeks.

Researchers did a systematic review Open a glossary item of studies in 2018. The researchers found that megesterol acetate compared with a dummy drug (placebo) had moderate evidence for weight gain.

Most of the weight gain seems to be fat and fluid rather than muscle mass.


Doctors use steroids for many different illnesses and conditions. The body naturally makes them. They are also made artificially and used as medicines. They come as tablets, liquids or injections.

Steroids can help to control chemotherapy sickness in people with cancer. These are drugs like dexamethasone or methylprednisolone. They can also improve appetite and food intake.

These drugs can also increase your sense of well being. They sometimes cause extreme happiness (euphoria). This is a benefit if you are feeling very low, anxious or depressed about your cancer. But some people may experience these mood changes as very unsettling.

Doctors sometimes use steroids to help people gain weight. But there can be problems if you take them long term. Much of the weight you gain on steroids is due to fluid retention.

After taking them for a few weeks, they begin to interfere with the production of protein in your muscles. If used long term, they can cause muscle wasting. So, you need to use steroids under the supervision of your doctor.

Anti sickness drugs (anti emetics)

Feeling and being sick is best controlled with medicines. These drugs are called anti sickness drugs, anti nausea drugs or anti emetics.

There are many anti sickness drugs to choose from. Tell your doctor or pharmacist if one drug does not work for you. They can often suggest another you can try.

Drugs for diarrhoea

The most commonly used drugs for diarrhoea are:

  • codeine phosphate
  • Ioperamide (Imodium)

All these drugs slow the movement of the bowel. Codeine phosphate is also a painkilling drug. But it is also used to treat severe diarrhoea because it causes constipation.

Drugs for constipation

These are called laxatives. There are different ones that work in different ways:

  • bulk forming laxatives work by swelling up inside your bowel, softening and increasing the amount of stool, which encourages your bowels to open
  • stimulant laxatives work by speeding up bowel movement
  • osmotic laxatives work by drawing more water into your bowel, making your stools softer and easier to pass


Painkillers are also called analgesics or analgesia. Severe pain can make you lose your appetite and feel sick. If your pain is under control you are more likely to feel like eating.

Last reviewed: 
09 Apr 2020
Next review due: 
10 Apr 2023
  • Megestrol acetate for cachexia–anorexia syndrome. A systematic review

    V Ruiz‐García and others

    Journal of Cachexia Sarcopenia and  Muscle. 2018 June; 9(3): 444–452

  • Cancer: Principles and Practice of Oncology (11th edition)

    VT DeVita , TS Lawrence, SA Rosenberg

    Lippincott, Williams and Wilkins, 2019

  • Nutrition and Cancer
    Edited by Clare Shaw
    Wiley-Blackwell, 2011

  • Electronic Medicines Compendium (EMC)
    Accessed April 2020

  • British National Formulary (BNF) - NICE

    Accessed April 2020

  • Managing Constipation in Adults With Cancer

    R Wickham

    Journal of Advanced  Practice Oncology 2017 March; 8(2): 149–161

  • 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.

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