Used Medicinal grade Bentonite clay for acid reflux,works within a few sips. Get a small bottle of water put in a teaspoon of bentonite clay (PH is 9.1) shake hard so it disolves in the water and take some sips. You will notice within the second sip the acid starts to calm down. A note; People with bad acid reflux have trouble sleeping, magnesium gets depleted when acid is on overload, a few sips of bentonite clay before bed you sleep like a baby. Magnesium' has a 'calming' effect for the mind and the physical muscles. There is magnesium in bentonite clay.