IMHO I totally agree with Hv about testing for stomach acid or lack there of. The Heidelberg test is a waste of money. I did it mainly to prove to people around me that my stomach acid was very depleted. I had been saying for quite awhile that I thought allot of my health problems stemmed from low stomach acid, and no one believed me, especially the Drs. I had one gastro Dr. tell me that you didn't need stomach acid when you got older.Can you imagine? You best believe I ran out of there. Go by your symptoms, and if Zypan helps you, that is a pretty fair indication that your digestive juices are lacking.