RefenesenTM Chest Congestion Relief DM Caplets 50"s, 100"s (Bottle in Box)RefenesenTM DM offers the maximum 400mg OTC Guaifenesin dosage available in a dye-free, immediate release caplet to loosen and relieve chest congestion. It also includes 20mg of Dextromethorphan to control coughs.RefenesenTM DM helps loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus. Helps make coughs more productive.RefenesenTM DM provides up to 2400mg Guaifenesin and 120mg Dextromethorphan daily.