The West Lothian Drug Action Team has launched a campaign in partnership with c-stores, supermarkets, off-licences and the police to target adults who buy alcohol for under 18s.
The campaign involves retailer posters calling on people to Act Your Age.
New alcohol consumption statistics from the Information Services Division of NHS Scotland indicate that 73% of 13-year-olds and 90% of 15-year-olds questioned in West Lothian had consumed alcohol, with 24% of the former and 40% of the latter having drunk it in the past week.
The most common sources for commercially bought alcohol reported by 15-year-olds were from shops, with a large majority admitting to having products bought for them by somebody else.
A spokeswoman for the Lothian and Borders Police said: "We recognise that the majority of shopkeepers actively prevent sales where there is a likelihood that the alcohol may be passed to persons under 18."