[cygaril]

Yes, me too - I had two weeks of constant headaches and both physical and mental exhaustion. I still went to work, but I got basically nothing done for the whole fortnight.

Still, I'm glad I did it - it was definitely an unhealthy addiction for me. I'm now 15 or so years mostly caffeine-free.

[graeme]

Same here. My digestion was worse when I was on it, as well as my overall energy levels.

It seems there is a gene that determines whether someone is a fast or slow metabolizer of caffeine. If I ever get such a test done I'll definitely check if I'm on the slow spectrum. It's associated with worse coffee outcomes.

https://well.blogs.nytimes.com/2016/07/12/for-coffee-drinker...