Guaifenesin is used to help clear mucus or phlegm (pronounced flem) from the chest when you have congestion from a cold or flu. It works by thinning the mucus or phlegm in the lungs.
This medicine is available both over-the-counter (OTC) and with your doctor’s prescription.
Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years of age. Using these medicines in very young children might cause serious or possibly life-threatening side effects .
Some of the side effects that can occur with guaifenesin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:
Less common or rare:
nausea or vomiting
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