Guvacine is a tetrahydropyridine alkaloid found in areca nuts. It is the N-demethylated derivative of arecaidine and the product of ester hydrolysis of guvacoline, both of which are also found in areca nuts as well. The compound is a potent and selective GABA reuptake inhibitor via GABA transporter 1 (GAT-1) inhibition. It shows poor bloodâÂÂbrain barrier penetration. Lime hydrolyzes guvacoline to guvacine.