I've had this work as a side effect from my bi lateral transforaminal epidural steroid injection in my L4/L5/S1 . First one lasted almost 5 months with the injection being repeated every 3 months. Last 2 injections did not provide lasting results. I'm assuming less lidocaine made it's way to the nerve area. My doctor assumed it was a side effect of the steroid and was shocked when I told him I had read it was the lidocaine. Hope this does have a clinical study. The results were instantaneous. Plaques fell off next day and skin was peachy and smooth in less than 3 days.