Vesamicol is an experimental drug, acting presynaptically by inhibiting acetylcholine (ACh) uptake into synaptic vesicles and reducing its release.

[2] Vesamicol can be broadly categorized as a cholinergic physiological antagonist, because it reduces the apparent activity of cholinergic neurons, but does not act at the postsynaptic ACh receptor.

Vesamicol causes a non-competitive and reversible block of the intracellular transporter VAChT responsible for carrying newly synthesized ACh into secretory vesicles in the presynaptic nerve terminal.

This transport process is driven by a proton gradient between cell organelles and the cytoplasm.

Blocking of acetylcholine loading leads to empty vesicles fusing with neuron membranes, decreasing ACh release.