I have been using this product for over a month now and each week am considerably more impressed. I do my martial arts work out at night and stimulant based energy products give me insomnia and prevent me from getting quality rest. That is why I originally tried this and it delivered. It makes me alert and focused for my workout, gives me endless stamina and endurance and really mitigates the burn so I can keep fighting. This is not a bodybuilding product so don't expect pumps or weight gain. Just good clean energy with no crash. In 30 days I have increased my intensity and duration considerably. The only negative is that some of the powder is not water soluble, so you have to mix with a small amount of water and shake the hell out of it before you kick it back so the particles are all swirling around. I use apple juice which mixes nicely with the hot cinnamon flavor.