I had been taking B1 for a while and slacked off, so now I got the bottle out and will re-start it, there is a survey here started by Cort in 2013 and I commented on it but don't know where it's located. Oh maybe here it is.
The High-Dose B-1 (Thiamine) Survey for Fibromyalgia and Chronic Fatigue Syndrome (ME/CFS) - Health Rising
A small Italian study suggests high-dose B-1 could reduce pain and increase energy in fibromyalgia and ME/CFS. Does it? Take the survey and let us know.