It has two active ingredients: Mucinex dm what's the difference? Guaifenesin is an expectorant that helps.

Webwhat is the difference between mucinex d and dm? Mucinex d and mucinex dm both contain guaifenesin as an active ingredient. Webthe main difference between mucinex, mucinex d, and mucinex dm is the active ingredients in each brand name. Webmucinex d and mucinex dm both contain the expectorant guaifenesin (which is contained as a single ingredient in mucinex). So, they’re both expectorants, or.

So, they’re both expectorants, or.