It is an easily defensible argument that this is a medical question rather than a chemistry one, however, I feel that it leans ever so slightly towards chemistry, and so I posted it here.
There is a "new" OTC stimulant being pushed around that shall remain unnamed so that this isn't flagged as an advertisement or anything. In looking at the list of ingredients, I don't see anything that would act as a stimulant anywhere in that list. Having said that, I'm not an expert.
So, I came to the experts. ;)
Here are the ingredients according to the bottle:
Just to clarify, the heart of this question is "Which ingredient is the stimulant?"