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Mytesi Side Effects

Generic name: crofelemer

Medically reviewed by Last updated on Dec 25, 2023.

Note: This document contains side effect information about crofelemer. Some dosage forms listed on this page may not apply to the brand name Mytesi.

Applies to crofelemer: oral tablet delayed release.

Serious side effects of Mytesi

Along with its needed effects, crofelemer (the active ingredient contained in Mytesi) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking crofelemer:

Less common

Other side effects of Mytesi

Some side effects of crofelemer 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:

More common

Less common

For Healthcare Professionals

Applies to crofelemer: oral delayed release tablet.


Common (1% to 10%): Acne, dermatitis[Ref]


Common (1% to 10%): Flatulence, nausea, hemorrhoids, abdominal distension, abdominal pain, constipation, dry mouth, dyspepsia, gastroenteritis[Ref]


The most common adverse reactions (greater than or equal to 3%) include upper respiratory tract infection, bronchitis, cough, flatulence and increased bilirubin.


Common (1% to 10%): Urinary tract infection, pollakiuria[Ref]


Common (1% to 10%): Decreased white blood cell count[Ref]


Common (1% to 10%): Increased bilirubin, increased alanine aminotransferase, increased aspartate aminotransferase, increased conjugated bilirubin, increased unconjugated blood bilirubin, nephrolithiasis[Ref]


Common (1% to 10%): Back pain, arthralgia, musculoskeletal pain, pain in extremity[Ref]

Nervous system

Common (1% to 10%): Dizziness[Ref]


Common (1% to 10%): Giardiasis, herpes zoster, procedural pain, seasonal allergy[Ref]


Common (1% to 10%): Anxiety, depression[Ref]


Common (1% to 10%): Upper respiratory tract infection, bronchitis, cough, nasopharyngitis, sinusitis[Ref]


1. Product Information. Fulyzaq (crofelemer). Salix Pharmaceuticals. 2013.

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.