In Each Extended-Release Tablet: Other Information: Each Tablet Contains: Magnesium 25 mg. Store between 20-25 degrees C (68-77 degrees F). 12 hour extended-release tablets. Guaifenesin 1200 mg/expectorant. Dextromethorphan hydrobromide 60 mg/cough suppressant. Extended-release tablets. Controls cough. Thins and loosens mucus. Questions or comments? 1-800-986-0369 (Mon-Fri 9AM - 5PM EST). Parents: Learn about teen medicine abuse www.StopMedicineAbuse.org.