[oftenwrong]

Apparently, that stuff is of questionable safety, as it contains DMAA:

http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm347270.ht...

https://www.nytimes.com/2013/04/13/business/fda-issues-warni...

[pvnick]

Take the recommended dose (one or two scoops) and you'll be fine. Overdose and your heart will stop. Same exact thing as any stimulant.