When I was working an early morning shift getting up at 3:30 I found them to be really helpful. It's a lot more effective in my experience than other methods of caffeine. Though I would recommend the 100mg versus the 200 because popping 400 at once had me feeling like I was gonna die on a few occasions. 300 seems like a solid shot in the arm dose I never experienced. It was either 200 or 400 for me baby, on top of my Adderall. Which basically does nothing for me now.