One in four underage alcohol drinkers consumes more than 20 units a week, a survey has claimed.
Researchers found alarming habits among thousands of young people aged 14 to 17 in north-west England.
One in two young people admitted drinking to get drunk, one in 20 drink alone and one in six regretted having sex after consuming alcohol.
But it also found the number of teenagers drinking alcohol at least once a week has dropped from 50% in 2005 to 38% in 2009.
The survey of 13,000 young people was carried out on behalf of trading standards services in the region and published by the Trading Standards Institute (TSI).
According to Bupa, men should not drink more than 21 units of alcohol a week and women should not drink more than 14 units.
TSI chief executive Ron Gainsford said: "We welcome this broad ranging survey, which provides valuable information for trading standards and other professionals concerned with the safety of our communities.
"It is encouraging that fewer teenagers in the North West are drinking weekly - but the response that a quarter are consuming more than 20 units a week, which is very close to the limit recommended for adult men, is alarming for these young people's own health and for the wider damage on local communities that alcohol abuse inflicts."
Richard Lindley, who worked on the survey, said: "The figures appear to substantiate that the underage sales operations by trading standards at retail premises are working.
"There has been a significant drop since 2007 of young people purchasing alcohol from shops and off-licences. It is important, however, that operations aimed at off-licences and newsagents continue, as a priority, to further the decline of the availability of alcohol to young people."
