How Long Does A Cup Of Coffee Keep You Awake?
How Long Does A Cup Of Coffee Keep You Awake? Caffeine has a half-life of about 5 hours. Someone who consumes 40 milligrams (mg) of caffeine will have 20 mg remaining in their system after 5 hours. When do effects peak? Levels of caffeine peak in the blood within about 15–45 minutes of consumption. Can