First 10 minutes:
Caffeine begins to enter the bloodstream causing a rise in heart rate and blood pressure.
15-45 minutes:
Caffeine levels will peak, creating a sense of heightened concentration.
30-50 minutes:
The liver will begin to react by absorbing more sugar.
1 hour:
Caffeine levels begin to drop and you may start to feel tired.
5-6 hours
At this point the body will have worked to reduce the caffeine content in your blood by half.
12 hours
For most people, the caffeine from the energy drink will be out of your bloodstream, but this will depend on age and activity levels.
12-24 hours
For regular Red Bull drinkers, this is the point where withdrawl symptoms will kick in. You may begin to feel irritable, constipated, and suffer from headaches.
7-12 days
This is the average amount of time it takes for the body to build tolerance to a daily dose of caffeine. So to continue feeling any impact at this point you would need to up your intake.
- NZ Herald