An independent study showed that it has more caffeine than the label claims.
There's also the issue of the deaths that have been linked to 5 Hour Energy, according to the FDA. The company says they don't know anything about it
They have been asked to remove the "no crash later" claim because it isn't true. It's just less of a crash than you might get from Red Bull.
I think their advertisements are very misleading. They attempt to make you think that thousands of doctors recommend their product, but if you listen carefully, you'll find that's not what they are saying at all. It isn't a doctor recommended product.
Shifty ads, inaccurate labels, and serious side effects.