What is Mucinex, and what is it used for?

Mucinex (guaifenesin and dextromethorphan hydrobromide) is an over-the-counter expectorant medication used to treat the symptoms of cough by loosening mucus and congestion.

Mucinex may be used alone or with other medications.

It is not known if Mucinex is safe and effective in children younger than 6 months of age. 

What are the side effects of Mucinex?

Mucinex may cause serious side effects including:

Get medical help right away, if you have any of the symptoms listed above.

The most common side effects of Mucinex include:

Tell the doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Mucinex. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Is Mucinex addictive?

No information provided

What is the dosage for Mucinex?


  • do not crush, chew, or break tablet
  • take with a full glass of water
  • this product can be administered without regard for timing of meals
  • adults and children 12 years and older: 1 or 2 tablets every 12 hours; not more than 4 tablets in 24 hours
  • children under 12 years of age: do not use

When using this product

  • do not use more than directed

What drugs interact with Mucinex?

No information provided

Mucinex contraindications, and pregnancy and breastfeeding safety

Do not use

  • for children under 12 years of age
  • if you are now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric or emotional conditions, or Parkinson's disease), or for 2 weeks after stopping the MAOI drug. If you do not know if your prescription drug contains an MAOI, ask a doctor or pharmacist before taking this product.

Ask a doctor before use if you have

Stop use and ask a doctor if

  • cough lasts more than 7 days, comes back, or occurs with fever, rash, or persistent headache. These could be signs of a serious illness.

If pregnant or breast-feeding, ask a health professional before use.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center right away.


Which illness is known as a viral upper respiratory tract infection? See Answer


Mucinex (guaifenesin and dextromethorphan hydrobromide) is an over-the-counter expectorant medication used to treat the symptoms of cough by loosening mucus and congestion. Serious side effects of Mucinex include hives, difficulty breathing, swelling of your face/lips/tongue/throat, severe dizziness, rash, and itching.

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 11/8/2021
All sections courtesy of the U.S. Food and Drug Administration