Robitussin, Adult Cough + Chest Congestion Dm Liquid Maximum Strength, 8 OzProduct Description Temporarily relieves cough due to minor throat and bronchial irritation as may occur with a cold. Helps loosen phlegm (mucus) and thin bronchial secretions to drain bronchial tubes. Non drowsy. For ages 12 and over. Product Benefits Ingredients Active Ingredients: In Each 20 ml: Dextromethorphan HBr, USP 20 mg; Guaifenesin, USP 400 mg. Inactive Ingredients: Anhydrous Citric Acid; Carboxymethylcellulose Sodium; FD&C Blue No. 1; FD&C