Drinking water won't cure a hangover.
The drink is recommended to help those cope with the effects of a heavy night but research has found that it actually makes little difference to the impact of boozing too much.
Scientists at Utrecht University in the Netherlands studied partying students and recorded hangover symptoms in those who drank water before going out and those who didn't.
The results showed that those who consumed water still had the same levels of nausea, exhaustion and pain as those who did not drink any.
The experts concluded in the journal Alcohol: "The consumption of water during, or directly after, a drinking session is not effective in preventing hangovers.
"And the amount of water consumed during the hangover is not significantly related to changes in severity."