The amino acids on the ingredient list are in a mixture with no breakdown on how much of each.
I really don't like products that do this, because is obscures the truth.

I would guess the main effects are caffeine oriented.

Also I see a skin flush warning on the original formula. This is odd because the niacinamide is a form not supposed to cause a flush at all. The caffeine free form has the niacinamide removed!
This is stranger still.

http://www.5hourenergy.com/healthfacts.asp

Notice that only the DECAF shows caffeine content.
Since Caffeine is the dominant ingredient that gives the boost,
its actual milligrams is missing from the Original formula listing and the Extra strength one.

That is deceptive and I personally would never use this based on the weird labeling and unknown qualities presented.
Of course, the tiny bottle itself does not lend itself to a proper listing either!