This Is The Best Time To Drink Your Coffee, According To Science

When cortisol, a hormone associated with alertness, dips, you’ll start feeling drowsy. That’s the moment to caffeinate.

This Is The Best Time To Drink Your Coffee, According To Science
[Image: Flickr user Moyan Brenn]

If you’re anything like certain members of the Fast Company staff, then you feel more or less undead until you have your morning cup of brains coffee. However, insight into the way our attention rises and dips throughout the day suggests that we can get more precise about the way we caffeinate–and thus become more productive.


How so? Because, as Steven Miller, the man behind brain blog NeuroscienceDC suggests, the way coffee affects your body is shaped by a few key factors. Those being:

  • Caffeine is a drug
  • Your body has rhythms, hormonal and otherwise
  • To use a drug wisely, you fit it to your rhythms

How do those points combine? To understand, Miller asks us to consider the insights of chronopharmacology, the study of the interaction between drugs and biological rhythms.

Your body has many rhythms: there’s the circadian one that drives your sleeping habits (and gets messed up by over-zealous snoozing), the ultradian one that tells us to unplug every 90 minutes, and most interestingly for our caffeinated purposes, the rhythm of the release of cortisol.

The character of cortisol

Cortisol is a hormone that’s gained a bad name: often referred to as the “stress” hormone, it increases the amount of sugar in your bloodstream and heightens your brain’s use of glucose, among other action-ready, danger-facing functions. If you’re releasing cortisol all the time–as chronically stressed people do– it can be super bad for you, since all that glucose can lead to diabetes and other nasty diseases.

However, cortisol isn’t always terrible: as Miller notes, your cortisol correlates to your alertness levels. And when is cortisol at its highest? As a University of Sheffield study has shown, you have the most cortisol between the hours of 8 a.m. and 9 a.m.

So if you take a cup then, it’s a tad redundant. As Miller explains:


… you are drinking caffeine at a time when you are already approaching your maximal level of alertness naturally. One of the key principles of pharmacology is use a drug when it is needed (although I’m sure some scientists might argue that caffeine is always needed). Otherwise, we can develop tolerance to a drug administered at the same dose. In other words, the same cup of morning coffee will become less effective

There are other cortisol peaks throughout the day, like between noon and 1 p.m. or between 5:30 and 6:30 p.m. The savvy coffee drinker, then, will enjoy her brew when her natural alertness levels are low, like between 9:30 and 11:30 am–that way you can get the most bang for your cup.

Hat tip: NeuroscienceDC

About the author

Drake Baer was a contributing writer at Fast Company, where he covered work culture. He's the co-author of Everything Connects, a book about how intrapersonal, interpersonal, and organizational psychology shape innovation.