when i was taking clen i took 500mg caps 2 caps before meals and workouts....here is something from andy's clen FAQ
"Taurine MUST be used with Clen at 3-5g daily. Clenbuterol depletes taurine levels in the liver which stops the conversion of T4 to T3 in the liver. Taurine allows the user to avoid the dreaded rebound effect and painful muscle cramps. It's a must with Clen. "