Remember - most fat-burners have a mild diuretic effect on the body. (. your body tends to lose water) You should strive to increase your water intake in order to compensate (unless you're preparing for a contest). Water plays an important role in transporting nutrients to muscles and shuttling waste out of the body. 1 - 2 gallons of water a day is recommended for most bodybuilders. Also, take thermogenics with more than just 8 ounces of water. That's the bare minimum that your body needs to swallow the stuff! I suggest taking at least 20 -24 ounces. That way, your body will remain hydrated, which is even more important if you use them pre-workout.
The use of Clenbuterol results in down regulation of beta receptors, and therefore, it is should be used for only short periods of time. A clen cycle generally lasts 2 to 3 weeks with a break in between cycles lasting equal to or longer than the cycle itself. The cycle should start gradually, slowly increasing the Clenbuterol dosage and then tapering off gradually. The average dose of clenbuterol is 60 to 120 mcg/day. Your best course of action is to start slow with a low dose, gauge the effects it has on your body, see how well your body handles it, and then slowly increase the dosage accordingly.