Yes. I felt burning and pain very shortly after using it. I tried many brands too. This used ot happen with almost every supplement I took so I gave them up years ago. I only use milk t histle now with every meal ( thank God it doesn't bother me cause my liver works overtime ), chlorella and my sauerkraut. I think this is a common occurance with leaky gut people becuase I've noticed posts before where people say they cannot use supplements ( sensitive ). I am getting better but it's been so slow. I rebound at times cause I am not strict enough. I just got sick of starving you know? I've managed to put on 10 pounds over the past couple years :-)