I had a similar experience about 2 years ago. Intense burning pain. I had to force myself to vomit. I think it was because I took it on a somewhat empty stomach and didn't drink enough water. I believe it was the cayenne that caused the burning. I was afraid to take it for awhile after that. Now I take it regularly and have never had the problem since. I make sure I take it with food and also drink a good amount of water. I really think it is a fantastic product. Sorry to hear you had such a bad experience with it.