Ecstasy tablets contain MDMA, though they usually have a mix of other ingredients too. Pure MDMA remains rare in New Zealand.

Prime Minister John Key is unconvinced by a doctor's claim that the pure form of ecstasy is safer than alcohol and should be legalised.

Emergency medical specialist and clinical toxicologist Paul Quigley told Fairfax Media there was mounting evidence that MDMA was one of the safest intoxicants around, especially when compared with alcohol. Liquor-related injuries and illnesses made up about two-thirds of late-night and weekend admissions at Wellington Hospital's accident and emergency department, he said.

Although Key said he had not seen any official advice on the safety of ecstasy, and was unfamiliar with Quigley's reasoning, he thought it unlikely his Government would legalise it. "Anything I've seen in relation to this drug has been deeply negative, so I can't see why it would be."

He believed the societal harm from such a move would be "very, very significant". Such legalisation would be a very different step from harnessing the non-psychotic medicinal properties of cannabis for patients such as Alex Renton, whose mother's quest to treat her son's prolonged seizures with cannabinoid oil hit headlines this month.

But Quigley's controversial call has been backed by the New Zealand Drug Foundation, and Associate Health Minister Peter Dunne said that, although the idea was a "long shot", he would discuss its merits with Quigley, the head of Wellington Hospital's emergency department.

Legalising and regulating the sale and manufacture of MDMA – or 3,4-methylenedioxy-methamphetamine – could put a dent in the black market for other more harmful drugs flooding the market, Quigley said.

In April, the hospital's emergency department dealt with a spate of people tripping violently on a potent new group of hallucinogens known as "N-bomb".

Quigley suspected most had bought the N-bomb unknowingly: "They all thought it was acid. I've seen a lot of acid freakouts, and this wasn't acid at all. They are really, really messed up."

MDMA should first be tested theoretically under the Psychoactive Substances Act (PSA) testing regime, which was enacted to regulate legal highs and party pills before they were made illegal last year, he said.

"There are political and moral barriers that society has to get through – and we may still find something that is better and safer than MDMA – but people will always take recreational drugs and society has to accept that at some some stage there will be a drug available that is a safe and acceptable alternative to alcohol."

That was unlikely to happen while domestic law was bound by United Nations drug control treaties, but Quigley said New Zealand could be a world leader and forge ahead with its own ideas of what substances were dangerous.

If MDMA passed the PSA's testing, it could be sold with an R-18 rating, in controlled and limited doses through chemists or "head shops", such as the Cosmic Corner chain, which would be subject to the same type of police scrutiny as outlets selling alcohol.

However, Quigley distinguished pure MDMA from what is often sold as "ecstasy", which could be mixed with other pills and powders and could be dangerous. Pure MDMA is still rare in New Zealand.

Dunne said "at this stage" the Government would be reluctant to legalise MDMA.

Reclassifying the class B drug as legal, then going through the process under the PSA to allow its manufacture, would take several years "on the remote assumption we decided to do it", he said.

However, he would discuss the merits of Quigley's argument when the pair met over the coming weeks.

Drug Foundation executive director Ross Bell supported legalising MDMA, and said a global shortage of the drug had led to a raft of new and unknown chemicals being sold as ecstasy.

"That's the reality – if we regulated drugs that we knew more about and were less harmful, then you'd go a long way to mitigating the harms that exist in the black market."

National Addiction Centre deputy director Simon Adamson said both MDMA and cannabis were "reasonably low-risk", warranted safety testing and could both be candidates for decriminalisation.

Chris Wilkins, of Massey University's drug research institute Shore, said that if MDMA passed the battery of clinical and toxicological tests required to get through the PSA regimes, and was shown to be low risk, it should be allowed to be sold.

"But I would almost be certain that level of evidence is not around."

Police said all questions regarding the legalisation of drugs should be directed to the Ministry of Health.

MDMA: GLOBAL DRUG SURVEY 2015 CONDUCTED IN PARTNERSHIP WITH GLOBAL MEDIA PARTNERS INCLUDING STUFF.CO.NZ

The survey says significant changes in MDMA since its first appearance in the 1980s include a rise in use in combination with other drugs especially alcohol, which increase the risks of unwanted effects, as well as diminishing the desirable effects of the drug, and an expansion in its use beyond the dance music/rave scene.

MDMA was the highest-ranked drug using the Net Pleasure Index in the 2013 survey, suggesting overall that pleasure and positive experiences associated with MDMA led few to seek treatment for their use.

In New Zealand 10 per cent of the survey's sample said they had used MDMA in the past year. Pills cost on average nearly $50 – the most expensive of the 18 countries canvassed.

MDMA is not risk free: last year's survey reported a three-fold variation in the percentage of users seeking emergency medical treatment (from 0.3 per cent in Switzerland to 0.9 per cent in the USA).

WHAT IS MDMA?