I had chronic POTS symptoms for years. Doctors couldn’t figure out what was wrong and I took medication just to function. Discovered that my body may not be absorbing vitamin B and was recommended Sulbutiamine. Started feeling the relief day 1 and everyone around me noticed the difference immediately. My health is back to normal and my active life has returned. I take one dose a day 3 days on and 1 day off with no negative symptoms. Very grateful this product exists.