ESPRESSO EXAMPLE

What remains from a 6 PM espresso?

The buzz can fade before the caffeine does. A half-life model makes that invisible remainder easier to reason about.

A simple example

A 63 mg espresso taken at 18:00 leaves roughly 32 mg at 23:00 when using a five-hour half-life. At eight hours, the same dose would leave about 41 mg. Actual espresso caffeine varies by dose and preparation; EFSA lists about 80 mg for a 60 ml espresso serving.

Why bedtime response still differs

Remaining milligrams are not the same as perceived stimulation. Habit, genetics, medication, pregnancy, and sleep pressure all matter. The estimate is most useful when you compare it with your own sleep over several days.