2 NEW FACTORY SEALED MUCINEX MAXIMUM STRENGTH GUAIFENESIN 1200 MG >> EXPECTORANT EXTENDED-RELEASE TABLETS. Key Benefits of Mucinex 1200 mg (12-Hour) Thins and Loosens Mucus: The 1200 mg dose of guaifenesin, an expectorant, works by reducing the viscosity (thickness) of bronchial secretions.



