How long does caffeine stay in the body?

Caffeine typically has a half-life of about 5 to 6 hours in the average adult. This means that after this time, approximately half of the caffeine consumed remains active in the body. Consequently, caffeine has a quarter-life of about 10 to 12 hours, which indicates the duration until about a quarter of the original amount is left in the system (1).

Individual Variability:

• Genetic Factors: Metabolism can vary based on genetic differences in liver enzymes, specifically those of the cytochrome P450 family. Some individuals metabolize caffeine more quickly or slowly due to these genetic variations.
• Sensitivity: Some people may feel the effects of caffeine more intensely or for longer periods, particularly if they have a slower metabolic rate for caffeine (2).

This variability can explain why some people can consume caffeine late in the evening and still sleep well, while others may experience disruption in their sleep patterns even from earlier consumption.