The reason many standard energy drinks stop working or don't work for desk jockeys like myself, is that they are designed more for "sports" energy than cognitive enhancement.
Think about it, writers don't need physical stamina and strength so much as they need focus and a cognition boost.
So standard energy drinks aren't viable for desk jockey's.
Often you're getting MORE caffeine and B vitamins in the standard Energy drinks, but the other stuff in it is trying to calm you down so the more you drink the more relaxing/calming ingredients you also get!
You end up in stimulation heaven, but feel conflicted because you're also very tired. Your brain is awake but your body is taking full advantage of the inositol and taurine which is saying relax, whoa boy easy now.
What's worse is if the actual energy components don't work, the relaxing agents still DO work so you feel tired (the irony of drinking an energy drink and feeling tired is due to this phenomenon). An energy drink won't work if there aren't certain prerequisites present too.
1. Drinking water and lots of it- especially with these energy drinks and even Nerd Focus.
2. If you're dehydrated your body won't process energy drinks very well- if your malnutritioned, the same thing.
3. If your body is worn out, you stayed up two days in a row, or if you're trying to do things that don't require PHYSICAL energy then the drinks will just amp you up making your fidgety.
This 3rd one is where Nerd Focus comes into play. It's an energy drink (physical stamina) AND a focus drink (mental and cognition stamina)- not caffeine based artificial focus, but real focus that happens when your brain is happy.
The calming ingredients also help calm the jitters caused by caffeine but there is a caffeine threshold where jitters are inevitable (different for different people).
The natural energy creator in energy drinks... the smart drug, nootropic ingredient (cognition enhancer/focus) is the N-L-acetl-l-carnitine and L-acetl-L'Tyrosine.
These enhance the body and give the mind a powerful ingredients it uses to create energy (ATP) but they also have powerful cognition enhancing effects.
The "L" and "Acetyl" parts are referring to precursor for Acetylcholine which is like adding new cell phone towers in your brain so more of your brain cells can communicate faster and farther across the brain...