Guaifenesin is an expectorant available in over-the-counter (OTC) medicines that make coughs more productive by loosening chest congestion and ridding the airways of bothersome mucus. Guaifenesin can be the only active ingredient in a cough medicine, or it can be found in multi-symptom cough and cold products. Guaifenesin may also be found in medicines that treat bronchial asthma.

Symptoms Treated

Symptoms Treated

More specifically: 

Chest congestion

Common Products

  • Little Remedies®
  • Primatene® Tablets
  • Triaminic®
  • Store Brands (ex. Walmart’s “Equate” store brand or CVS Health store brand)

Dosing Information

Different types of products containing this active ingredient have different strengths. That’s why it is always important to read and follow the Drug Facts label. Most medicines warn against use of an active ingredient for longer than 7-10 days. Stop use and ask a doctor if symptoms persist.

Safety Guide

Safety Guide

Guaifenesin is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label directions.

Ask a healthcare provider before use if:

  • If you are allergic to guaifenesin or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems.
  • You have breathing problems (such as emphysema, chronic bronchitis, asthma, smoker's cough) or large amounts of mucus.

Do not use if:

  • Do not give an OTC cough medicine or multi-symptom cough and cold medicine containing guaifenesin to a child under the age of 4.

Stop use and ask a doctor if:

  • Your cough lasts for more than seven days, returns, or occurs with a fever, rash, or persistent headache. These additional symptoms could be signs of a more serious illness.
  • You take too much. Immediately contact a healthcare provider or the poison control national helpline at 800.222.1222.

What are the side effects of guaifenesin?

  • Nausea or vomiting may occur.
  • A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.