Why does caffeine only affect me hours later?
                                
                                
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                                    4 min read                                
                            
                                According to the Sleep Foundation, the half-life of caffeine can range from 2 to 12 hours, a massive variability that explains why its effects differ so widely among people. This significant variance is often the key to understanding why some individuals feel the stimulating effects of a morning coffee much later in the day, sometimes long after the initial buzz has subsided.