Mucinex Sustained-Release Capsules

• Though rare, the most common side effects of Mucinex Sustained-Release Capsules are nausea and vomiting. Other potential side effects are allergic reactions, including but not limited to difficulty breathing, hives, chest tightness and facial swelling.
  
  As with any side effect from medication, seek medical attention if you have severe side effects related to use of Mucinex.
  
  

Mucinex Children's Granules

• The most common, though rare, side effects of Mucinex Children's Granules are nausea and vomiting. Other potential side effects are allergic reactions, including but not limited to difficulty breathing, hives, chest tightness and facial swelling.
  
  As with any side effect from medication, seek medical attention if you have severe side effects related to use of Mucinex.
  
  

Mucinex Junior Strength Granules

• The most common, though still quite rare, side effects of Mucinex Junior Strength Granules are nausea and vomiting. Other potential side effects are allergic reactions, including but not limited to difficulty breathing, hives, chest tightness and facial swelling.
  
  As with any side effect from medication, seek medical attention if you have severe side effects related to use of Mucinex.
  
  

General Side Effects

• General side effects of Guaifenesin--the active drug in Mucinex--include upset stomach, dizziness, headache and rare skin-related issues like rashes.
  
  

Reporting Additional Side Effects

• If you experience additional side effects you think may be related to Mucinex usage, please report them to the Food and Drug Administration. You can do so by calling 1-800-FDA-1088 (1-800-332-1088), or by visiting www.fda.gov.