Reporting side effects

Medicines are an important part of healthcare, but any medicine can have side effects. Reporting side effects of medicines makes medicines safer and helps protect everyone’s health.

What are side effects?

Side effects are symptoms you feel when you take a medicine, including prescription medicines, over-the-counter (OTC) medicines, herbal remedies, vitamins and supplements.

Side effects range from mild, such as drowsiness or feeling sick (nausea), to severe, life-threatening conditions that need to be treated in hospital. Some side effects go away once your body gets used to the medicine, but others can last much longer. Read more about side effects

Why should I report side effects?

Reporting side effects makes medicines safer and helps protect everyone’s health. It can prevent future harm to people taking the same medicine. It also helps to ensure safer prescribing and safer use of medicines in the future.

By reporting your side effects, you help to improve patient safety and protect public health, and also improve medicine information and education.

Why is it important to monitor side effects? 

Although medicines are carefully tested in clinical trials, there are limits to those trials. These include:

  • the number of people studied in the trial
  • the people studied may not include special groups
  • only some uses of the medicine are studied
  • medicines may be tested for a shorter time period than it is prescribed. 

The benefits of people reporting their experience include:

  • identifying reactions that only happen in some people, which may not have been picked up clinical trials
  • that information from special groups is noted
  • the long-term effects become clearer
  • interactions with other medicines or even food get identified 
  • more information about how severe and how common reactions and side effects are.

How can I report side effects?

If you think your medicine has caused a side effect, talk to your doctor. They may be able to lower your dose or change the medicine. Don't suddenly stop taking your medicine unless your doctor tells you to.

It is important to let your doctor, pharmacist or nurse know about your side effects. Reporting side effects helps protect everyone's health.

You can also report side effects yourself through the Centre for Adverse Reactions Monitoring (CARM). CARM accepts reports from everyone but they will try to involve the doctor, nurse or pharmacist to make sure they are also aware of the reaction.

CARM can be contacted through:

CARM is a database of New Zealand-specific information on adverse reactions (side effects) to medicines and vaccines. CARM monitors this information to identify any issues to help with the safe use and prescribing of medicines. This may lead to changing prescribing or monitoring of medicines to ensure the safety of medicines registered in New Zealand.   

Learn more

Side effects of medicines Health Navigator, NZ
Medicines and falls risk
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Medicines and sexual problems Health Navigator, NZ
Medicines and weight gain Health Navigator, NZ
Severe allergic reactions (anaphylaxis) to medicines (Maori) Medsafe, NZ 
Medicines for depression or other mental disorders and difficulties with sex (sexual dysfunction) Medsafe, NZ


  1. Medication side effects – how likely are they to occur? Sussex Partnership, NHS, UK 
  2. What are side effects? NHS, UK
  3. Understanding the frequency and severity of side effects: linguistic, numeric, and visual representations  American Association for Artificial Intelligence, US, 2006 
Credits: Health Navigator Editorial Team. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 20 Oct 2020