Webdec 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. 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. Webwhat is the difference between mucinex d and dm? Mucinex d and mucinex dm both contain guaifenesin as an active ingredient. So, they’re both expectorants, or. It has two active ingredients:
