Cazz-Stacker II, Ripped Fuel,etc. all have Ephedra (aka - Ma Huang)in them. They will give you a ton of energy and also keep you up the whole night. There are a ton of these products on the market so don't waste a fortune on the ones that are really expensive. Thermal Cuts, THermo - Pro, etc. are all thermogenic formulas with the same ingredients. Try to get one with both Ephedra and Guarana in them - if you take 2 before you go out you will feel a pretty big adrenaline rush after about 45 minutes!