It can certainly happen, yes. I would experiment with smaller doses of caffeine maybe, but always make sure to have adequate sucrose/protein/nutrients when you're taking it. I find caffeine pills are easier to assess than coffee and just make sure I take it with a meal or substantial calories.Thanks, do you not find you become jittery?
Coffee is more hit or miss for me. I tend to dilute the coffee pretty strongly with sugar/honey/maple syrup and milk/salt/gelatin to combat the potential adrenaline response.
But in general if I'm eating enough nutrient dense foods with an adequate sugar source then I don't notice any downsides to the pure caffeine. In fact, I'm sometimes able to fall asleep after taking a 200mg pill in the middle/late day - something Ray has mentioned can happen in response to thyroid supplements, which would follow as caffeine can definitely have thyroid-mimetic effects.