Sides of clen can be nasty yea!!! cramps will wake you in the night - happend to me and felt like my leg was going to snap off!! But i increased my potasium and electrolites and didnt happen again. Make sure you also take a Arganine supp as it lowers your 'T' levels in the liver! and keep well hydrated!!!! Start off slow/low and increase per day... but when your at 8-10 tabs a day then take only every 2 days as this is its half life time. I did a 2 week cycle with lots of cardio and dropped my carbs - managed to loose 14lbs!! Its ace stuff if you get it all right!!! - also when the thermogenic effects start to wear off then stopp taking it cos its no longer doing its job!