Since the beginning of time, mankind has yearned to drink a cup of coffee at 5 PM and go to sleep at 10. But now there's an entire scientific subfield and several companies pandering to this absurd fantasy.
Here's a simplified diagram of caffeine metabolism:
Caffeine is converted to a different stimulating chemical called paraxanthine by a liver enzyme called CYP1A2, over a half-life of ~5 hours. Then the same enzyme converts paraxanthine into other non-stimulating chemicals that don't matter, over a half-life of about three hours. Kman on Less Wrong has graphed the total effective concentration over time:
Over the course of hours, the liver converts caffeine into paraxanthine. These are (by assumption) equally potent, so total effective concentration (the dashed red line) goes down slowly.
(Why does it go down at all? Because of the simplification in the diagram above: only about 80% of caffeine is converted to paraxanthine; the rest is converted to other, less active metabolites.)
By hour ten, paraxanthine predominates, the liver is mostly converting paraxanthine to other non-stimulating chemicals, and effective concentration continues to decrease. In this model, we see that the effective half-life of caffeine is close to ten hours1!
What if we want it to be less? There are three levers we can pull: the enzyme, the metabolite, and the starting chemical.
Podden och tillhörande omslagsbild på den här sidan tillhör
Jeremiah. Innehållet i podden är skapat av Jeremiah och inte av,
eller tillsammans med, Poddtoppen.
