Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making
it easier to cough out through your mouth.
Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated
blood vessels can cause nasal congestion (stuffy nose).
The combination of guaifenesin and phenylephrine is used to treat stuffy nose and sinus
congestion, and to reduce chest congestion caused by the common cold or flu.
Guaifenesin and phenylephrine may also be used for other purposes not listed in this
medication guide.