Abusers with limited access to urban drug supplies have discovered that Azaperone, which is available on prescription from vets, can be stolen from farms where they are sometimes left lying around after animals have been treated.
A report by the Institute for the Study of Drug Dependency, commissioned by the BBC's Countryfile television programme, focuses on the cases of 15 people in Bridlington on Humberside - but researchers fear that the problem is countrywide.
The tranquilliser is widely used on pigs and is administered before the animals give birth or undergo transportation, or to prevent aggressive behaviour.
It is not on the controlled drugs list so that, technically, it is not illegal to take it. The Home Office said that action could be taken against abusers who trespass or steal in order to get hold of the drug.
Abusers say it produces a mild euphoria, but it has been known to have a knockout effect. There is no research to suggest what a 'safe' dosage might be.
One drug abuser, who asked to remain anonymous, told Countryfile: 'They are more readily available than street illegal drugs or imported drugs and they are already made up.
'I would be able to go to a farm and get some because farmers just leave them lying around.
'Farmers will just leave them on the window sill after injecting a pig or a cow until they need them the next time.'
Alan Dean, who carried out the study, said: 'What separates rural drug use from urban drug use is simply opportunity.
'People in small villages cannot easily get hold of heroin or cocaine, so they will look elsewhere to get intoxicated.'Reuse content