I have used Grenade Thermo Detonator previously as well and it does work well both as a "fat burner" and also as a good "pre-workout", provided that your gym training is intense and diet is strict. Personally for me, I am not able to develop the tolerance for full serving of it, but even with 1/4th of the serving (i.e. taking only 1 capsule for the day) it still does give me good results.