It has two active ingredients: Webboth mucinex d and mucinex dm contain the active ingredient guaifenesin, which is an expectorant that helps loosen and thin mucus in the airways, making it easier to cough. It has two active ingredients:

Mucinex d and mucinex dm both contain guaifenesin as an active ingredient. So, they’re both expectorants, or. Webwhat is the difference between mucinex d and dm? Guaifenesin is an expectorant that helps.