It's different for everyone, I remember I was having heart palpitations from any of the -racetam's after a while and I heard Tim Ferris actually mention that side effects like this are common.
IMHO for the same desired 'bang' you might be better off with a Lion's Mane, Cordyceps, etc. supplement, I've been able to do that sort of thing without anything funny happening.
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“Love takes off the masks that we fear we cannot live without and know we cannot live within. I use the word "love" here not merely in the personal sense but as a state of being, or a state of grace - not in the infantile American sense of being made happy but in the tough and universal sense of quest and daring and growth.” - James Baldwin