Nicotine is quite unique stimulant because it's a parasymphatomimetic.

I found some nicotine gum (2mg) in my closet that I bought like a year ago to experiment. It only made me anxious back then but I had high amounts of anxiety regardless.

Decided to give it a new try. Chewed one gum (2mg nicotine) a while ago with my morning coffee, feeling a bit more stimulated and "sharpened" than usual, could be placebo though. I think I'll try different doses in next few days and report back. Supposably theanine cancels out the pleasant-addictive qualities of it, I might try if black tea modifies the effects.

By binding to nicotinic acetylcholine receptors, nicotine increases the levels of several neurotransmitters – acting as a sort of "volume control". It is thought that increased levels of dopamine in the reward circuits of the brain are a major contributor to the apparent euphoria andrelaxation, and addiction caused by nicotine consumption. This release of dopamine induced by nicotine is thought to occur via a cholinergic–dopaminergic link, mediated by a neuropeptide, ghrelin, in the ventral tegmentum.[sup][30][/sup] Nicotine has a higher affinity for acetylcholine receptors in the brain than those in skeletal muscle, though at toxic doses it can induce contractions and respiratory paralysis.[sup][31][/sup] Nicotine's selectivity is thought to be due to a particular amino acid difference on these receptor subtypes.[sup][32]

Wikipedia[/sup]