Caffeine intake does not significantly increase cortisol levels in habitual users, but may prolong cortisol's effectiveness.

“you wake up, and you don't ingest caffeine. Fine and, in fact, beneficial to hydrate with water and electrolytes.”

“bright light with exercise um with caffeine these things will all increase cortisol”

“The first group is one that I commonly encounter. These are people that say, "Listen, I don't care what I hear out there. I want my coffee or I want my yerba mate, which is my preferred source of caffeine, first thing in the morning, right? Ideally, even before water." Well, there I'd say please drink water first, but even if you're not going to, sure, go ahead and drink your caffeine. Drink that caffeine. It's not going to boost your cortisol that much. But make sure you're doing a bunch of other things. Bright light viewing, we'll talk about exercise in a moment, etc. do a bunch of other things to make sure that morning cortisol spike is really, really high because that's what you want.”

“simply giving you an opportunity to extend the life of that morning cortisol pulse. Caffeine is a great way to do that.”

“If you're somebody who regularly drinks caffeine, you now know that it's not going to boost your cortisol levels that much, maybe a little bit depending on how much you drink. If it's a typical amount for you, meaning your caffeine adapted to that amount of caffeine, probably not much cortisol increase will come from drinking that amount. However, it will prolong the duration of cortisol's effectiveness in your bloodstream.”

“This is where the recommendation that I've been making for some years now of delaying your caffeine by anywhere from 60 to 90 minutes comes about. You now know that caffeine for a habitual user is not going to increase your cortisol levels that much. However, you also now know that drinking caffeine will extend the life of cortisol somewhat. So the logic here is if you drink your caffeine not immediately after waking but let's say an hour after waking or 90 minutes after waking, it's going to flatten out a bit the downs slope of that cortisol as you transition from late morning into the early afternoon.”

“if you're drinking that caffeine shortly after waking up or shortly close to when you get that big cortisol spike, it's going to make the downs slope of that cortisol spike a bit more gradual.”

“which for the rest of us habitual caffeine users, you're drinking our caffeine and it's harder and harder to get. That's just the nature of caffeine tolerance.”

“Because caffeine, if you are a habitual caffeine user, you drink caffeine daily or three times a week, you won't get much of a cortisol increase from caffeine.”