• helps with stuffy nose, chest and sinus congestion, and wet cough. • combines two medications in a single product for convenience. • available over the. dec 6, 2023 · mucinex d and mucinex dm both contain the expectorant guaifenesin (which is contained as a single ingredient in mucinex). Guaifenesin is an expectorant that helps. Mucinex dm what's the difference?
