Leader Mucus Relief DM, Extended-Release Tablets, 20 ct (Compare to Mucinex® DM) Leader Mucus Relief DM combines maximum-strength Guaifenesin and Dextromethorphan HBr in an extended-release formula for powerful 12-hour congestion and cough control. The dual-action approach thins and loosens mucus while suppressing cough, enabling clearer breathing and improved comfort throughout the day or night. With just one dose lasting 12 hours, you avoid frequent redosing and maintain consistent relief. Featuring the same proven active ingredients as Mucinex® DM, Leader delivers comparable efficacy at exceptional value.