The level of caffeine in your blood peaks about one hour later and stays at this level for several hours for most people. Six hours after caffeine is consumed, half of it is still in your body. It can take up to 10 hours to completely clear caffeine from your bloodstream.

Does caffeine go to your bloodstream?

Caffeine is absorbed from your stomach. It reaches its highest levels in your bloodstream within an hour or two. Caffeine can make your blood pressure go up for a short time.

Can caffeine affect you 8 hours later?

Negative Effects of Caffeine

Caffeine can have a disruptive effect on your sleep. The most obvious effect of the stimulant is that it can make it hard for you to fall asleep. One study also found that caffeine can delay the timing of your body clock. These effects will reduce your total sleep time.