I have small fiber SFN, some inherited version. Started alpha lipoic acid and within 2 weeks started getting back feeling in my feet. After 6 months I have regained most of my feeling. I started at 300mg bid then after a couple of months went to 600 mg because it had made an improvement/decrease in my back pain. After 6 months my feet “feel” better and my back pain (nerve pain) is very well controlled. No more Tylenol and advil (for back).