Well, I've been experimenting with thiamine for close to 3 weeks now and am finding that I am very sensitive to a low dose - 25 - 30 mg., cannot tolerate anything higher. But this low dose is noticeably helping my energy, and at the same raising my blood pressure, strangely enough, because thiamine is supposed to lower BP. My BP has been in the normal range for years (120 - 125/75 or so) and now is going up to 140, I know, a bit high, but energy is better so am hoping it will settle down. A year or two ago I tried 400 mg. of thiamine and it was too much and I never bothered to work with a lower dose. I was doing some research on lactic acid recently, thinking of PEM, and read that thiamine deficiency can cause lactic acidosis, which I know is different than PEM, but there's definitely a connection between lactic acid and PEM. So that led me to try thiamine again. I'm 99% sure I avoided one crash since on the B1, and also recovered more quickly from another crash. But, I still do crash. But it hasn't been that long. I've been taking a B complex that has 25 mg. benfotiamine, but this added B1 is rather amazing. I'm almost too sensitive to the benfotiamine, one 40 mg. dose kept me wired for about 3 days so I'm staying from it for now and just sticking with plain thiamine. I'm going out of town tomorrow to see kids and grandkids for Thanksgiving (yay!), though will be exhausting of course (boo!). Anyways, I won't be around to reply to this thread for awhile after today. There's more info about B1 I'd like to post, including some very interesting articles, but don't have time today. I already take B complex, metafolin, methylB12, P-5-P, pantothenic acid, and a ton of other stuff. But thought I would just post this in case it might help someone else.