It's a fat-soluble form of thiamine (Vitamin B1) which crosses the blood brain barrier, something regular B1 can't do. It appears to help a great many people with foot and hand pain and tingling from diabetes, and it might help protect against Alzheimer's. I just got some, and we're trying it here. Our daughter's feet are very painful much of the time, so I'm hoping this will fix that. And I still have pain in a nerve that was pinched before my first back surgery. Not sure if it will help with that, but I'm hoping.