David O'Halloran, 18, a first year student at Stirling University, vanished in the early hours of January 18. His body was not found until April.
Although the cause of Mr O'Halloran's death has never been determined, toxicology tests concluded he had high levels of GHB (gamma hydroxybutyrate) in his blood, urine and hair, backing up his family's theory that he had become disorientated by a spiked drink.
His mother, Donna O'Halloran, has received support from Tennent Caledonian Breweries, which has provided beer mats with a photograph of her son and the words: "Don't be another spike in statistics."
Pub-goers put a drop of drink on to the mat and it uses chemical indicators to change colour if illicit drugs are thought to be within the liquid.
The move comes as it emerged there will be no fatal accident inquiry (FAI) into Mr O'Halloran's death. Officials at the Crown Office have told his family they will be taking no further action, leaving his mother no closer to the truth about why her son died.
Police Scotland had already concluded there was no evidence to support the family's assertion the student's drink was spiked.
But Mrs O'Halloran, from Kilmaurs, East Ayrshire, said she is looking into whether she can appeal the decision. She said: "In a basic sense, all unusual deaths should be investigated on the basis of being suspicious until proven otherwise, instead of not suspicious until shown otherwise.
"There are gaping holes in the circumstances of what happened to David and it is his final right to get a fair and proper inquiry. An FAI would not only confirm our suspicions about what happened, but also put safeguards in place to prevent similar tragedies."
Mr O'Halloran, who was studying maths and education, went missing in the early hours of January 18, having decided to leave a taxi on his way back from a night out with friends in Stirling. He was spotted jogging towards his residence, but CCTV footage later showed him staggering and disorientated as he walked in the wrong direction.
His body was found three months later in a field by a sheep farmer, more than two miles from the university.
A toxicology report by Glasgow University found GHB - a class C drug derived from an anaesthetic - in Mr O'Halloran's blood, urine and his hair, with the levels of the substance 100 times higher than produced in normal adults. Because of its sedative effects and tasteless and odourless quality, GHB is one of the most common drugs to use when spiking someone else's drink.
The forensic team, however, was unable to conclude whether the high levels of the drug in Mr O'Halloran was as a result of his taking the drugs recreationally, or it having been put in a drink.
A separate post-mortem examination by NHS Lothian concluded the cause of death was unascertained and said the theory he died of exposure was speculative.
Mrs O'Halloran said: "Why is it in Scotland that some unusual deaths are never truly investigated, but written off as unascertained? Some are looked into, some are classed as suicides, but then some, like my son's, are just forgotten about.
"I believe an FAI should be held because David did not follow the criteria set out for being drunk and hypothermic as predicted by so-called experts, therefore surely that rings alarm bells for further investigation to take place."
Mrs O'Halloran recently met with Justice Secretary Kenny MacAskill to discuss tougher licensing laws, including enforced limits on the number of drinks per customer, and hi-tech coasters that can detect drugs.
A Crown Office spokesman yesterday confirmed no hearing would be held.
He added: "After careful consideration of the facts and circumstances of the case, Crown Counsel concluded it was not a case in which it would be appropriate to hold a fatal accident inquiry."