Guaifenesin, the only medicinal product in common use as an expectorant, is an ingredient in many cough medicines, such as Anti-Tuss, Dristan Cold & Cough, Guaifed, GuaiCough, and some Robitussin products.
These other treatments include suctioning, nebulizer treatments, and the administering expectorant drugs.
There is some dispute, even among experts, about whether guaifenesin is an effective expectorant.
The mucilage also acts as an expectorant which helps break up any mucous that is present.
Expectorant cough medicines, unlike cough suppressants, do not stop the cough.
"What's the difference between an expectorant and a cough suppressant?"
Thus as it passes out by the bronchial mucous membrane it increases the amount of secretion and so acts as an expectorant.