Harrassed by law enforcement and struggling to maintain lengthy supply chains, organised crime groups have long effectively been selling fake cocaine on the Scottish market.
Now, according to the first ever Scottish breakdown of the anonymous Global Drugs Survey or GDS, published today, they have been found out by those to whom they peddle.
The survey found Scots are less happy with the value for money of their cocaine than abusers anywhere else in the world, bar Australia.
On a scale of 1 to 10, users in both countries rated the drug at 2.5; this despite the fact that, according to the GDS, a gram of the drug costs more than three times as much in Australia, £190, as it does in Scotland, £62.
"Generally drug purity decreases the farther the drug is from its source," a spokesman for Police Scotland said in reaction to the survey, which had some 600 responses in Scotland. Police and other law enforcement agencies will see customer discontent as a key sign of success they are blocking imports of the drug.
Cocaine in particular can be highly adulterated on the Scottish market. Just 18 months ago Scotland was being declared the "fake coke" capital of the world with cocaine so diluted that there was just a fraction of a per cent of the drug in every gram sold.
Law enforcement agencies increasingly target the adulterants of cocaine, such as benzocaine and caffeine, which are legal.
Adam Winstock, the consultant psychiatrist who runs GDS, believes dissatisfaction reflects, in Scotland, more on the active content of the drug than on the cost. "What happens is that the price of cocaine stays the same and the quality goes down," he said. "That is also why we are now seeing markets develop for even more expensive premium cocaine. But it is really expensive - and not necessarily that much better."
Dr Winstock, however, stresses that perception that cocaine is poor value for money can have other effects. "If people aren't happy with cocaine they could try powder MDMA," Dr Winstock said, referring to a drug better known in pill form as Ecstasy.
Medically, near zero-ingredient cocaine also presents problems. The adulterants used, such as benzocaine, may mimic some of the effects of cocaine, including numbness in the nose. But trying the real drug can be "frightening" if you take a full dose after consuming the fake product, said Dr Winstock.
Scots users were more content with the price-quality ratio of their MDMA, ranking it as seven out of 10 for both pills and powder.
A gram of MDMA, according to the survey, sells at just over £40 in Scotland, slightly below the international average. A single pill was put at £10, the world average.
Scotland is thought to produce a lot of high-potency cannabis, in indoor plantations run by Chinese organised crime groups. However, Scottish users were still unhappy with the value for money of the drug. They rated it at six out of 10, slightly below international average, despite the fact the its price, at £13 per gram, is well above the world sample mean.
Scots cannabis users, meanwhile, were among the least likely to be caught by the police with cannabis in the last 12 months.
This is despite vast numbers of reported stop-searches looking for drugs. Users also reported they were unlikely to face law enforcement consquences.
A Police Scotland spokesman disputed this.