Caffeine typically starts affecting you within 15 minutes of consumption, with peak levels in your bloodstream occurring around 30 to 60 minutes after intake
. The duration caffeine stays in your system varies widely depending on individual factors such as genetics, age, body weight, medications, smoking, and pregnancy
. The key measure to understand how long caffeine lasts is its half-life—the time it takes for the body to eliminate half of the caffeine consumed. On average, caffeine’s half-life is about 3 to 6 hours, but it can range from as short as 1.5 hours to as long as 12 hours in some people
. This means that if you consume 100 mg of caffeine, about 50 mg may remain in your system after 3 to 6 hours, and smaller amounts can persist for much longer. Caffeine may not be fully cleared from your bloodstream until 10 to 12 hours after consumption, which is why it can affect sleep if consumed too late in the day
. Experts often recommend avoiding caffeine at least 6 to 8 hours before bedtime to minimize sleep disruption
. In summary:
- Effects begin within 15 minutes and peak around 30-60 minutes after intake.
- Half-life ranges from 3 to 6 hours on average, but can be 2 to 12 hours depending on the person.
- Caffeine can remain in your system for up to 10-12 hours.
- Avoid caffeine at least 6-8 hours before sleep to prevent interference with rest.
These variations mean that how long caffeine "wears off" depends on your metabolism and sensitivity, but generally, its noticeable effects last around 4 to 6 hours, with residual caffeine lingering longer
