Coffee, in conjunction with aspirin, is “the best cure for a hangover,” according to researchers at Thomas Jefferson University, Philadelphia, in the US.
Well, it is if you are a rat…
The team introduced enough ethanol to produce a headache to laboratory rats, and then four to six hours later (to ensure the rats were properly hung over), they fed them caffeine and aspirin-based anti-inflammatory drugs.
The researchers discovered that the caffeine/aspirin mixture blocked acetate formed by alcohol in the body and eased the rodents’ discomfort. 
“None of the commonly cited cures for hangovers could have caused this response,” according to researcher Dr. Michael Oshinsky. However, he did not reveal if the researchers had also tried feeding rats some of these “commonly cited cures” as a comparison,. These apparently include drinking lots of water, eating a meal of fried egg, bacon, sausages, toast and tomatoes, or, a personal favorite, taking the “hair of the dog” which is “typically a Bloody Mary” (vodka and tomato juice) the morning after.