I know that caffeine tolerance is built up really quickly and that caffeine isn’t harmful. What about all those B-vitamins that speed up your metabolism? Do we build up a tolerance to those quickly? Any problems with extended use? My brother’s been taking one of those a day and I’m worried about him…it just seems to me that if it didn’t have any ill effects than everyone would be using it? I know that you guys aren’t medical professionals, but I was hoping I could get a quick answer.

Topics: health, medicine, energy, medical advice, caffeine, supplements, supplement