In Each Tablet Other Information: Each tablet contains: Sodium 20 mg. Store at 20-25 degrees C (68-77 degrees F). Avoid high humidity and excessive heat above 40 degrees C (104 degrees F). Naproxen sodium tablets, 220 mg (NSAID). Pain reliever/fever reducer. For temporary relief of headache pain. Strength to last 12 hours. Questions or comments? 1-800-395-0689 (Mon-Fri 9AM-5PM EST).