Oh, I had the same problem. Even if I slept well during the night, I felt sleepy. So I had to drink coffee or energetic drinks to be more active. Sometimes I could drink up to 4 energetic drinks a day, but it's not the best idea, as I found out. From this article beezzly.com/how-to-store/how-long-does-red-bull-last, I found out the effect of Red Bull and how many time it stays in our organism. It's a very informative article, and I think it will be useful for others to read it because that drink is popular.