LONDON (Reuters) - A hair of the dog, a prairie oyster or a cup of sugary tea really can help ease the suffering of the morning after, Britain`s New Scientist said on Wednesday. The magazine asked scientists around the world whether such hangover cures really work and concluded that most of them help a bit. But a complete remedy for the pains of over-indulgence remains a distant prospect. Part of the problem is that scientists have yet to agree on what a hangover really is. The liver converts alcohol first into a poisonous substance called acetaldehyde and then into acetic acid, which is passed out of the body in urine. Some believe hangovers are caused by an excess of poisonous acetaldehyde waiting to be converted. But some scientists say that methanol, found in its highest concentrations in dark alcoholic drinks like red wine and cognac, is to blame. The liver takes 10 times as long to break down methanol as it does the alcohol itself. Carl Waltenbaugh suggested a new remedy - N-acetyl-cysteine (NAC), an amino acid supplement available in many health food stores. Eggs too are rich in cysteine, explaining why "prairie oysters" made from raw eggs may work. One of the most commonly employed remedies - drinking lashings of water - may be the one of the best, the magazine said. Drinking plenty of water before collapsing into bed helps prevent dehydration and washes the alcohol out of the brain. And that sugary cup of tea the next morning? That helps ease hypoglycaemia caused when alcohol breaks down sugar stores in the liver, leaving the victim weak and jelly-like the next day.