Long post, sorry. Nicotine: what actually has human evidence behind it, and what is extrapolation from animals?
The comparison group matters more than the compound when the outcome is something as fuzzy as focus.
I have started logging dose, time, and sleep because otherwise the anecdote is just a mood.
Sleep is the limiting factor and it compounds quietly for a fortnight before it is obvious.
Would like a narrow answer rather than an enthusiastic one.
Sterility is the part people wave through and it is the part that actually bites.
Test one thing at a time. It feels slower and it is the only way to learn anything.
Loose evidence is not nothing, but a washout either side is the only reason to trust your own take.
Read methods.
Underdosing and tolerance are indistinguishable from the inside, and everyone picks the flattering explanation.
This is the kind of post the forum exists for.
Narrow conclusion. How long have you been on nicotine?
Same here.
Stupid question: how do you know whether what is in the vial matches the label at all?
Baseline first.
Log dose, time and sleep. Ten seconds a day and it turns the anecdote into something you can look at.
Same here.
Read methods.
Test one thing at a time. It feels slower and it is the only way to learn anything.