Guaifenesin is an expectorant that helps. 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. Webdec 6, 2023 · mucinex d and mucinex dm both contain the expectorant guaifenesin (which is contained as a single ingredient in mucinex).

Mucinex d and mucinex dm both contain guaifenesin as an active ingredient. So, they’re both expectorants, or. It has two active ingredients: It has two active ingredients: