Hi
Ephedrine free doesn't mean stimulant free. And most items marketed as Stimulant Free actually do contain a lot of stimulants, they just don't contain Ephedrine.
This product already contains caffeine, and it also contains Bitter Orange. Bitter Orange is on the Consumer Reports "Dirty Dozen" list and has been targeted by the FDA recently due to the very serious side effects it can cause. Bitter Orange produces an ephedra-like stimulant effect and is linked to high blood pressure, increased risk of heart arrythmias, heart attack, and stroke. I wouldn't be surprised if it isn't banned in the near future. Another warning on the label is "Exceeding recommended serving may cause serious adverse health effects including heart attack and stroke." I'm
assuming that adding additional caffeine would result in the same thing.