I have had mouth Ulcer all the time for so many years, so often that I would have 3~5 ulcers at the same time every month, and would take over a week to completely heal. I didn't intent to take this as preventing mouth Ulcer but for my blood supplement. I have low blood pressure (due to heavy period) and my doctor recommended me to take iron. After finishing doctor prescription iron supplement, nothing seem to change so I was looking another kind to see if it make any different. So I found this one. The first couple month I did not have any Ulcer or sometimes I do and it would go away after 2/3 days!! I was so happyyy. After finishing the first bottle, I stop for couple of months, the Ulcer came back. I start taking this again and they go away! So I would recommend anyone to take this if you have mouth Ulcer often due to Vitamin B12/ Folic acid deficiencies. The only thing I didn't like is the taste, kinda like a tart soy sauce. But still better taste than some other iron supplement I have tried