I've had MANY fat burners, mostly for energy and a workout kickstart. On my list is ECA stacks, Clenbuterol, thermorexin, among a few others. venom hyperdrive has been the most effective for me. I did a lot of research before taking it and read a million reviews. All in all it's a great product that sweems to get solid results. Not a bad price either, and since they are so strong and dosages are small, a little bit goes a long way.