**Abstract**

Ethanol with the molecular formula C2H6O is a clear, colorless, volatile liquid with a pleasant smell made by fermentation of sugar. Ethanol is one of many kinds of alcohol and is the only type of alcohol that can be consumed. Apart from consumption, ethanol is used for several other purposes such as fuel to power engines, as a disinfectant (because of its bactericidal activity), as a solvent and preservative as well as serving as the primary ingredient in the preparation of alcoholic beverages. In this chapter, the author describes how ethanol is metabolized in the body, genetics behind ethanol metabolism, metabolic pathways and hosts for ethanol production, ethanol and malnutrition, why ethanol is considered as a drug and effect of ethanol on neurotransmitter [gamma-amino-butyric acid (GABA), glutamate, dopamine, and serotonin] systems. The author further explains the effect of ethanol on antidiuretic hormone (vasopressin).

**Keywords:** ethanol, neurotransmitters, antidiuretic hormone, GABA, glutamate, dopamine, serotonin, metabolism
