A German court said in a ruling published Monday that hangovers are an "illness", in a timely judgement days after the annual Oktoberfest beer festival began in Munich.

The case landed before judges in Frankfurt when plaintiffs claimed a firm offering anti-hangover "shots" and drink powders to mix with water was making illegal health claims.

"Information about a food product cannot ascribe any properties for preventing, treating or healing a human illness or give the impression of such a property," the sober ruling from the superior regional court read.

"By an illness, one should understand even small or temporary disruptions to the normal state or normal activity of the body" -- including the tiredness, nausea and headaches the company claimed its product could polish off, they added.

In fact, doctors have long since coined the word "veisalgia" as a specialist medical term for the morning after the night before, the judges noted.