The Coffee Timing Mistake You Might Be Making for Years

Cutting coffee wasn’t the answer. Moving my last cup earlier made my nights noticeably easier.

Two pieces of coffee advice circulate at opposite ends of the day. One says to wait 90 minutes after waking before your first cup, so you do not interfere with a morning cortisol surge. The other says to stop drinking caffeine well before bed. Both sound like timing rules from the same body of science, and many people follow one while ignoring the other.

The evidence behind them is very uneven. One rule has controlled experiments and measured consequences behind it, and the other has an appealing mechanism and little direct testing. The mistake worth examining is optimizing the end of the day you can feel while neglecting the end where the consequences are harder to notice.

(This is built from published research and describes no one’s personal experience. I changed “I made” in the title to “you might be making” because I can’t verify a personal story.)

The morning rule: a plausible mechanism, an untested prescription

The logic of delaying coffee goes like this. Cortisol rises in the first hour after waking, a pattern known as the cortisol awakening…