Everybody knows that too much caffeine can make you jittery and anxious. Did you know that an overdose can kill. The caffeine absorbs right through your skin when you handle it. So you don't know how much you're getting right there.So, how come you can still buy it? Because caffeine processed into powder is classified as a multi-purpose food additive - which means it's safe for consumption, and perfectly legal to sell. What's the takeaway from this? Don't risk your life by using powdered caffeine. If you want a caffeine kick, stick with coffee - and leave it at three cups maximum a day.