A former government drugs advisor says the risks of taking laughing gas are lower than drinking alcohol.

Professor David Nutt, a psychiatrist and neuropsychopharmacologist based at Imperial College London, was one of the scientists behind the recent Channel 4 programme, Drugs Live: The Ecstasy Trial, on the effects of MDMA.

He says laughing gas (nitrous oxide) very rarely causes serious harm especially when compared to alcohol and tobacco. But he warned there are risks.

“Laughing gas is an unusual anaesthetic and pain reliever and when given in hospital it is mixed with the oxygen which our bodies need,” he told the Ham&High.

“Problems occur when people take it recreationally without getting oxygen.

“In hospitals, the gas in the tank is already mixed with oxygen whereas in recreational use it is usually pure, so users must be responsible for their oxygen.

“Secondly, in hospitals people are under medical supervision so if things go wrong they can be responded to.

“Hospitals also use a product manufactured to pharmaceutical standards. Recreational users do not usually find problems with purity but there are risks there.”

Nitrous oxide, or laughing gas, is a “dissociative” drug – which means the user might feel disoriented from the situation they are in, and even from their own body.

When someone inhales the gas, usually through a balloon on the party scene, it rapidly dissolves into the bloodstream and hits the brain within seconds.

Effects vary and are rarely the same twice, but a rush of dizziness and euphoria is normal.

“Nitrous gas is not illegal to possess but it is illegal to sell for the purposes of using it as a drug,” said Professor Nutt.

“When people sell it in clubs and parties, they are breaking the law, often without being aware of it.”

He added: “For recreational users, the benefit is simply fun, so it is impossible to make an objective judgement of how much risk the fun is worth, though we do it every time we go swimming or trampolining.

“Most people are happy to accept the risks of alcohol, so we should be careful with demonising drug users who decide that nitrous oxide is worth the risks.”

The common way of using laughing gas is to fill a balloon from a whipped cream charger.

“If this method is used, the drug is very rarely seriously harmful because if someone becomes so deprived of oxygen and they begin to lose consciousness, they will not be able to hold the balloon to their lips and will generally breathe air again,” said Professor Nutt.

“That does not mean it is completely safe. A heartbeat can become erratic from oxygen deprivation. If you had a pre-existing heart condition it could be risky.

“I want to emphasise that the risks of nitrous oxide, while they exist, are lower than those of alcohol and most other drugs.

“Many risks can be prevented through a little knowledge.”