Comment by jorvi
13 hours ago
Yes, but it might also be that you're drinking "coffee" (I assume you mean drip / pour-over) in the morning when you are just out of bed and have almost nothing in your stomach. Whereas the espresso you're drinking at a shop later in the day, probably already with breakfast in your stomach and maybe you're ordering a snack with it.
why would it matter what's in your stomach? caffeine goes pretty quickly to the blood stream, right?
Caffeine is a stimulant, acting on the sympatheitc nervous system. If you're also activating the parasympathetic nervous system, like by eating a meal, the effect won't be as strong.
Another effect of caffeine is as an adenosine re-uptake antagonist. Adenosine levels are usually low in the morning, so the effect is small. Later in the day, it can have a bigger effect on how alert you feel.
> A high carbohydrate meal consumed prior to caffeine ingestion significantly reduced serum caffeine concentrations and delayed time to peak concentration
https://www.sciencedirect.com/science/article/abs/pii/S14402...
having a full stomach has a moderating effect on most drug uptake.
I heard that the anxiety from caffeine is worse when you haven’t eaten. No time to check resources for that at the moment