Mucinex DM Cold and Cough Relief 600 mg - 30 mg Strength Tablet 20 per Box - 20 Count BoxAbout Mucinex DM Guaifenesin Dextromethorphan HBr Cold and Cough Relief (20 Units) Each tablet contains 600 milligrams of guaifenesin (which helps break up mucus) and 30 milligrams of dextromethorphan HBr a cough suppressant Mucinex DM controls coughs and thins and loosens mucus Immediate and extended release There are 20 12 hour relief tablets in a box Description: Cold and Cough Relief Mucinex DM 600 mg 30 mg Strength Tablet 20 per Box