brother was on this, dehydrated him from the inside out. nose bleeds, constantly chapped lips (real bad) bloodshot eyes. painful to watch, and IIRC he had to get blood drawn to check liver values or maybe kidneys or something. but the outcome was definetly worth it. strong stuff.
he didnt seem to have any problems, just drink a LOTTTTTT of water.
ive also heard theories how it can have permanent effects on behavior?