Starts neutralizing acid in seconds! New cooling sensation. Calcium carbonate. Cool action. Heartburn. Reliefchews. Questions or comments? 1-800-986-0369 (Mon - Fri 9am - 5pm PST). Other information: Each chewable tablet contains: calcium 300 mg. Store at room temperature. Avoid excessive heat above 104 degrees F (40 degrees C). Avoid excessive humidity. Close cap tightly after use.