Delsym Adult Cough Suppressant Liquid, 12 Hour cough suppressant in Grape flavor has a patented time-release medicine that goes to work fast to silence cough for a full 12 hours, up to 2 times longer than other cough liquids*. *Among OTC liquids per dose. Contains Dextromethorphan Polistirex, Extended-Release Suspension (Cough Suppressant.) Works both Day or Night, Alcohol-Free.