RG,
I think that these performance/workout enhancers are pretty much hype...and not necessary for the average person's routine. Better to stick to a healthy diet, multi vitamin and your regular workouts...(assuming you are doing 3 or more times a week combo of cardio weights/strengthening exercises and stretching.)
Even Gatorade, so favored by weekend warriors is a waste of money, when water will suffice for anyone doing a moderate to even high workouts. Really only elite athletes need these extra electrolytes and suppliments.
I also did read that there may be an interaction with the C4 and SSRI's...so you will need to check with your doctor about its safety for you.
Sorry to be a 'Debbie Downer'...just want you to be safe...and save your $$!
S.C.