Teachers, parents and pupils have received warning about the dangers of the drug Mephedrone - sold legally online as plant food - in a bid to avert what police and drugs workers fear could become a teenage drugs epidemic.
Information leaflets about the drug, which has become prevalent across Scotland and is particularly popular among young people, have been issued by Tayside schools.
Police are also issuing questionnaires to secondary pupils in Dundee, Perth and Kinross and Angus about the drug, which teachers claim is rife in some schools. It is said to have effects similar to Ecstasy and cocaine.
Police say primaries have been largely unaffected by the spread of Mephedrone - also called "bubbles", "drone", or "meow meow". But that could change, warned Inspector Wendy Symington, Tayside police drugs co- ordinator.
"It is a dynamic situation with `bubbles' - things change daily," she said. "One day it might not exist in a school, the next day it could just get out of hand. You just don't know because it is so prevalent."
The UK Government's new drugs adviser, Professor Les Iversen, recently described the spread of the drug as "quite scary".
The problem is not confined to Tayside, according to Detective Superintendent Willie MacColl, national drugs co-ordinator with the Scottish Crime and Drug Enforcement Agency. "It is prevalent across the whole of Scotland," he said. "Tayside is perhaps ahead of the game in terms of getting information about it out to schools."
The drug, a plant food not meant for human consumption, was "attracting youngsters in particular" who thought it was harmless because it was legal and readily available on the internet, he said.
Little is known about its short- and long-term health effects, and possession could still lead to arrest if, as has been found, packages contain illegal substances, he added.
Fergus Ewing, the Scottish Government's community safety minister, raised concerns about the drug last week with the Home Office.
But Detective Superintendent MacColl believes the answer is to make "credible and reliable information" available, since those pushing "legal highs" are quick to market new materials when the law catches up.
An information leaflet issued by Menzieshill High in Dundee cites the potential side-effects of the drug as: agitation; irritability; dizziness; pupil dilation; erratic jaw movements; headaches; increased heart rate; and raised blood pressure.
In Dundee, five users suffered non-fatal overdoses over just one weekend in November. Dundee drugs worker Gareth Balmer said Mephedrone had a "compulsive edge to it" and teenagers were selling their possessions to fund their habit.
Mr Balmer estimated that a capsule of Mephedrone could be bought online for pound;3-6, with a gram providing 20 to 30 capsules.