I definitely felt a increase in energy when taking it, but highly recommend not taking it on an empty stomach or at least with a meal. Doesn't say this anywhere on the bottle and maybe it's just assumed you should, but I felt absolutely horrible the times I took this and not eating at the same time.

I gave this product a poor review on Jan 2, 2012 due to lack of support from Kaspersky. Thanks to the vendors help I have had my problem solved and continue to use this software to protect my computer. On more than one situation the software has warned me of impending danger to my computer. I trust Kaspersky and only wish they had helped me earlier.