Beverages such as liquor, wine, and beer, contain a chemical called ethanol. There are a number of ways that ethanol may be triggering migraine episodes. First, ethanol is a direct vasodilator; in some individuals, vasodilation or the dilatation of blood vessels may cause migraine attacks. Second, ethanol is a natural diuretic; this leads to the excretion of salt, vitamins, and minerals from the body through the kidneys. Excess consumption of ethanol may produce dehydration and chemical imbalances in the body.

Alcoholic beverages also contain other chemicals called congeners. Congeners are byproducts of alcohol being fermented or distilled, and they impart the specific tastes and flavors that make each beverage unique. These congeners also have a variety of effects that can trigger migraine, alter other chemicals in the body, and induce the hangover effect if consumed in excess. Alcoholic beverages that are darker in color contain a higher level of congeners. Fructose, the naturally occurring sugar from fruits, helps return portions of the body’s chemical balance back to normal following ethanol consumption.

Many with migraine, and most with cluster headache, are sensitive to alcohol, even in small amounts.