I have a slight suspicion that every time I consume something with caffeine it has a specific effect on me.
A good cup of black or green tea: Slight headaches at some times.
A cup of coffee (from work coffee machine): Depending on strenght slight attention issues or headaches.
A cup of coffee from a coffee shop which roasts its own coffee: One time a bit of stronger attention issues than the work coffee.
I usually notice it right away after consuming.
But I also have a very strong issue with staying hydrated.
Usually drink 0.5-1l per day until I notice the usual dehydrated-headache or when I am really focused and loosing it at times.
Usually it’s less prevelant at evening/night times.
4 to 5 double espressos a day plus my ritalin just to maintain a clear head.
If I don’t have to do lots of detail tasks (like if I’m doing yard work on the weekend, then my requirements drop.
More than a triple-shot makes my stomach a little uncomfortable, but I tend to tank stimulants. Almost every other medication I’m quite sensitive to, but stimulants don’t do much.
Also I drink like 2 litres of water a day minimum.