A lot of folks on Health Unlocked PD forum seem to be having very favorable response to Thiamine, mostly in pill form. Some are using thiamine injections. I tried thiamine injections 3 times and felt worse. It made me tired, irritable and with a headache each time it was given. I gave up on it. I tried high dose thiamine supplements for 3 months and never saw any improvement. Though lately I'm thinking of giving another try. As for injections, I understand they sometimes use aluminum as a stabilizer/preservatives in in injectable liquid thiamine. Maybe that is the reason I found it intolerable.