I have no idea if the product is correctly labeled, but how do you make sure of that? Preworkouts seems to be the #1 product category that makes athletes fail drug tests, because so many of them were and are spiked with drugs.
If I was a trainer I would be afraid to vouch for any of them.
Just to be clear, this is for my consumption only. I would never recommend for any of athletes to take any pre-workout. We have a complete list of banned products and substances from the NFL and NCAA. We make sure that everything we carry in stock in my facility is NFL/NCAA approved.
Three weeks ago one of my returning baseball players came in with a C4 pre-workout. I basically told him that C4 is probably one of the strongest on the market and followed with "what the hell are you doing taking that shit" and explained to him that it's been recalled once before then put back on the market. This was last Thursday. Friday he left for a tournament in Arizona, returned Sunday and in the middle of the night suffered a major heart attack at 21 years old. He had no history of heart problems in the past and no history (that he was aware of) of heart disease in his family. Was released last night with 50% heart function.
I don't know if it was an underlying problem that was never caught that the C4 might have triggered or just an underlying problem. Either way, his baseball career is over but he's alive.