If you’re looking for the toughest chest congestion medicine to break up the mucus that’s bothering you, call in Maximum Strength Mucinex. Maximum Strength Mucinex SE powers through chest congestion for 12 hours so you can say goodbye to retaking medicine every 4 hours. Guaifenesin, the active ingridient in Mucinex SE, helps relieve chest congestion by thinning the mucus in the bronchial passageways to make the cough more productive. The bi-layer tablet releases immediately and lasts for up to 12 hours.* Mucinex In…Mucus Out®