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Niclosamide Side Effects

Applies to niclosamide: oral tablet chewable

Along with its needed effects, niclosamide may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Some side effects of niclosamide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less Common

  • Abdominal or stomach cramps or pain
  • diarrhea
  • loss of appetite
  • nausea or vomiting


  • Dizziness or lightheadedness
  • drowsiness
  • itching of the rectal area
  • skin rash
  • unpleasant taste

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

More about niclosamide

Consumer resources

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