For frequent, persistent coughs, Robitussin® Cough & Chest Congestion DM thins mucus to relieve chest congestion and gets your cough under control. Robitussin® acts to suppress coughs and thin mucus so your cough is more productive, all with a non-drowsy formula now in a portable liquid-filled capsule. The product controls cough, relieves chest congestion and thins and loosens mucus.