Carbachol (Carbamoylcholine chloride), an analog of acetylcholine, serves as a valuable tool in the investigation of various physiological responses mediated by nicotinic (nAChR) and muscarinic (mAChR) acetylcholine receptors. These responses include smooth muscle contraction, gut motility, and neuronal signaling. Known for its agonistic properties, Carbachol activates both nAChR and mAChR, with reported Ki values ranging from 10 to 10,000 nM for different receptor types and experimental preparations.