Arecoline, the principal active alkaloid in the areca nut, is known for its ability to induce euphoric sensations. Since ancient times, arecoline has garnered attention for its therapeutic potential in addressing psychiatric disorders and alleviating gastrointestinal ailments. However, in 2020, the International Agency for Research on Cancer has classified arecoline as 'probably carcinogenic to humans' (Group 2B carcinogen), supported by compelling mechanistic evidence. The mechanism of action of arecoline has been extensively studied, but the results of these studies are scattered and lack systematic integration and generalization. In this paper, we have systematically summarized the mechanism of arecoline within the oral cavity, central nervous system, cardiovascular system, and digestion system, in terms of both health functions and toxic effects. In addition, we found some concentration-effect relationship between arecoline in the central nervous system and digestive system, i.e., low doses are beneficial and high doses are harmful. By summarizing the mechanisms of arecoline, this review is poised to provide in-depth and valuable insights into the clinical practice and targeted therapy of arecoline in the future.