Webmucinex 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 d and mucinex dm both contain guaifenesin as an active ingredient.

It has two active ingredients: Mucinex contains guaifenesin only and is used. Mucinex dm what's the difference? So, they’re both expectorants, or. Webthe main difference between mucinex, mucinex d, and mucinex dm is the active ingredients in each brand name.

Webthe main difference between mucinex, mucinex d, and mucinex dm is the active ingredients in each brand name.