Teenagers drinking on streets, in parks and at home when parents are away are more at risk of harm than those boozing in pubs, a study says.
Teens are most likely to get drunk at a friend's house when parents are away
Researchers found children who drank in unsupervised places were more likely to injure themselves and get badly drunk.
The Joseph Rowntree Foundation study also found under 18s drank for self confidence, "the buzz" and to escape.
Earlier research has shown that UK teenagers are among the heaviest drinkers in Europe.
More than a quarter of 15 and 16-year-olds were said to indulge in excessive drinking at least three times a week.
Most frequent location for getting very drunk
39% At friend's home when parents away
12% Own home when parents away
Lester Coleman, co-author of the latest report, said he was particularly concerned about the teenagers who were drinking for fun in unsupervised locations as they were the most likely to be injured.
And he added: "It seems possible that access to the more supervised environment of pubs served to reduce the levels of risky behaviour among some young people who had been drinking heavily since their teens."
From interviews with 64 14 to 17-year-olds based in the south-east of England, the team found three quarters of the instances of being "very drunk" were in unsupervised locations, with the vast majority at home or a friend's house when parents were away.
Parks and streets also proved popular.
The teenagers told researchers they were more likely to take drugs, compromise personal safety, get in trouble with the police, have unprotected sex and sustain injuries when they had been drinking in unsupervised locations.
But the researchers said those who got drunk in pubs, which tended to be the older age group, were also at risk.
Sophie Davison, of Alcohol Concern, agreed drinking in unsupervised places was more risky and urged parents to set an example.
"Children's attitudes and behaviours are initially set by families so a sensible drinking example set by parents seems to be particularly important.
"If a child is learning from their peers, rather than their parents, they are in danger of spiralling out of control and their drinking habits can become more problematic later in life."
And Martin Plant, professor of addiction studies at the University of the West of England, added: "There is no doubt if young people are drinking in dodgy places they are more at risk."
He suggested parents should make sure they knew where their children were and what they were doing.
He also said it could be beneficial to introduce drinking at home to get children used to alcohol.