Arecoline is an agonist at all muscarinic receptor subtypes, though with different potencies at different subtypes.

The stimulant effects of arecoline — the alertness and enhanced concentration that make betel nut attractive to users — are thought to be mediated primarily through M1 receptors in the brain.

The increased salivation that betel nut produces is a M3 receptor effect.

The cardiovascular effects are mediated by M2 receptors.

The central nervous system effects of arecoline — the cognitive enhancement and stimulant properties — are particularly relevant for understanding why the ancient foragers would have been motivated to maintain the habit.

The M1 receptor-mediated effects include enhanced attention, improved working memory performance, and general cognitive activation.