Caffeine mostly. They like to advertise that in only contains as much caffeine as a cup of coffee, but they don’t tell you that it’s a super caffinated extremely strong cup of coffee or a really large one such with twice as much caffeine as a normal 8 oz cup. And it’s way smaller.
in addition to that it contains an overdose level of several vitamins that may or may not keep you more alter as a side effect. Overdoses are still not good though, even if your body can generally handle it. Other various ingredients are equally questionable, but may contribute, or may not.
Latest Answers