The feedback from people taking craze say how amazing it is. It's touted as not being massively reliant on caffeine either as ice mentioned.
My fundamental problem with 'colloquial' feedback stems from some of the bro-science out there, whereby (for example):
- gym-goers will take beta alanine in doses that are too high, get parasthesia as a result, and mistake it for 'energy' in their workout;
- people taking pre-workout supplements and mistaking the effects of shedloads of caffeine for ingredients like citrulline malate (which does actually work over a period of weeks to improve aerobic fitness and exercise capacity), creatine, etc.
I'm not disputing the claims that Craze works at all, but that a lot of the stuff they stick in it does not have any evidence to support it doing what they claim, over and above the caffeine (the tyramine analogue, NMT, just increases blood pressure, for example, yet is claimed to potentially maybe perhaps increase focus in rats... go figure).
If there is a 'mystery' ingredient that they don't declare, then great, and if people find it really works for them, then even better. However, the placebo effect will probably have a very strong influence over this, so I remain unconvinced about the
actual benefits.
However, as always, I am very happy to eat my hat if there is anything over and above colloquial opinion in these matters.