I tried to find some comparable studies, here's one that seems particularly relevant, showing the effects of caffeinated gum: http://www.militaryenergygum.com/

I tried to find some comparable studies, here's one that seems particularly relevant, showing the effects of caffeinated gum: http://www.militaryenergygum.com/wp-content/uploads/Bioavailability2.pdf http://www.militaryenergygum.com/wp-content/uploads/Bioavail... (take a look at the second graph) TL;DR: Yes, even with oral absorption, you probably won't feel anything after 5 minutes, and you'll be wired at 15 minutes. This toothpaste definitely won't work "on the spot", but 10-15 minutes is still quick enough to get you going by the time you're dressed and out the door.