When cold and flu symptoms like body pain, headache, and mucus congestion strike, reach for Maximum Strength Mucinex Rapid Clear Day and Night caplets. This medicine starts working fast to help relieve cold and flu symptoms. DAYTIME CAPLETS: Acetaminophen - Pain Reliever/Fever Reducer: Provides powerful headache relief, body pain relief, and sore throat relief. Guaifenesin - Expectorant: Targets bothersome mucus congestion by thinning and loosening mucus, providing excess mucus relief. NIGHTTIME CAPLETS:Acetaminophen - Pain Reliever/Fever Reducer. Dextromethorphan HBr - Cough Suppressant: Reduces the urge to cough to help you get to sleep. Triprolidine HCl - Antihistamine: Helps relieve runny nose, sneezing, itchy throat, and itchy/watery eyes. Trust Mucinex for powerful relief from your worst cold and flu symptoms.