Compare to Robitussin Cough Plus Chest Congestion DM active ingredients. Basic Care Tussin Cough Plus Chest Congestion DM targets the source of your cough to thin phlegm and mucus and control frequent coughing. Taken every four hours, each dose contains the powerful combination of dextromethorphan HBr 20 mg, a cough suppressant, and guaifenesin 200 mg, an expectorant. The DM formula is reliable and effective at providing cough, chest congestion and mucus relief. In peak cold season, trust this non-drowsy cough syrup in pleasant raspberry flavor to control your cough. Alcohol and gluten free. Dosage cup included. For ages 12 and over.