In brief drinking alcohol causes hypoxia, a state of oxygen deficiency on the brain, and impairs the brains ability to use oxygen; although hangovers are believed to be mainly caused by dehydration. This lack of oxygen is also a main aspect, the ability of supplementary oxygen to clear the mind, detoxify the blood and increase the bodies energy has been report by many to eradicate the symptoms of hangovers.
Scientifically speaking it takes 3 oxygen molecules to break down one alcohol molecule into acetaldehyde, and subsequently into carbon dioxide and water.
The extra oxygen the body intakes; the sooner the alcohol will be broken down into non toxic substances.
Flood your body with O2 after a hard night to relief yourself from the symptoms of the dreaded hangover.