When cold and flu symptoms like body pain, headache, cough, and mucus congestion strike, reach for Maximum Strength Mucinex Rapid Clear Day and Night Liquid Gels. Daytime Liquid Gels:. Acetaminophen – Pain reliever/fever reducer: Provides powerful headache, body pain, and sore throat relief. Guaifenesin – Expectorant: Thins and loosens mucus to relieve chest congestion. Nighttime Liquid Gels:. Acetaminophen – Pain reliever/fever reducer. Dextromethorphan HBr – Cough suppressant: Reduces the urge to cough to help you sleep. Doxylamine succinate – Antihistamine: Relieves runny nose, sneezing, itchy throat, and itchy/watery eyes. Count on Mucinex for powerful relief from your worst cold and flu symptoms.