Drug-testing at summer festivals has revealed some MDMA pills are two-times their normal dose.

New Zealand's summer of parties is riding a wave of super-strong ecstasy.

Drug testing group Know Your Stuff has been touring festivals around the country checking people's drugs are what they were sold as.

And it seems New Zealand's dealers are becoming a dangerously honest, and generous, bunch.

KEVIN STENT/STUFF NZ Drug Foundation executive director Ross Bell says its time the law caught up with testing black market drug-testing at festivals and parties to help get better information about what was in the drugs people were taking.

Despite being early in the festival season the amount of MDMA - or E - tested by Know Your Stuff that was indeed MDMA was higher than ever before, the group's director Wendy Allison said.

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Most pills ranged between 80 and 120 milligrams of MDMA but at one festival a person - who said they got the drugs from Amsterdam - had a single dose with an estimated 580mlg of the active ingredient.

"It tested to be mostly MDMA - we couldn't find anything else in it."

That was easily the most-potent E find of the summer so far, but pills were often turning up two-times their normal dose, she said.

While MDMA was generally not fatal, users could overdose through "serotonin syndrome" where the body lost the ability to regulate heat.

There have been three known ecstasy-related deaths in New Zealand, the first of which is thought to have been linked to the phenomenon, New Zealand Drug Foundation executive director Ross Bell said .

The only way people could get specific information on black market drugs was with checking.

If the public and authorities really wanted to know what types of drugs people were taking and issue good warnings then the law needed to catch up, he said.

Many festival organisers - despite wanting the service - were still too nervous about their liability and Bell said both festivals and drug-testers needed greater legal protection.

The Misuse of Drugs Act makes it illegal for festival organisers to knowingly allow recreational drugs on their premises.

"If you want to get 100 per cent information about what's on the black market then test the drugs people are putting in their mouths."

The information could also help authorities such as police avoid embarrassing public announcements, Bell said.

He was referring to the retraction by police on Wednesday - after they took back claims ecstasy use was linked to a violent stomach bug that plagued the Rhythm & Vines festival in Gisborne over New Year's.

Letting people know when drugs where strong, mixed with other drugs or not what they were sold as often resulted in people choosing not to take them, Bell said.

Testing of recreational drugs is currently being carried out in a legal grey area. Bell said the legislation, developed in the 1970s, around drug use is obsolete and urged the government to modernise the Act to allow new health innovations to happen.

Know Your Stuff has urged users to be aware high-dose MDMA pills may well be out there, and to approach "all substances sold as MDMA or ecstasy with extreme caution. The safest approach is to not take it at all."

Using volunteers Know Your Stuff has been testing substances at events for three years.

Last summer the group and the Drug Foundation checked more than 300 drug samples at music festivals across the country.

Because people take drugs regardless of the law the group has a harm reduction philosophy using proven information about substances so users can understand risks and make safer decisions.

WARNING: GREEN GUCCIS, YELLOW ROLEXES AND PINK PORSCHES

Know Your Stuff recommends approaching specific pressed pills with caution including green Guccis (rectangular, bright green, Gucci logo), yellow Rolexes (shaped like the Rolex crown, bright yellow).

Another pill that may contain an excessive dose is bright pink, shaped like a shield, and has the Porsche logo - users have reported unpleasant experiences and testing found they may contain dangerous pharmaceutical agents in addition to high doses of MDMA.

WHERE TO GET HELP

Alcohol and Drug Helpline 0800 787 797. Text: 8681. For urgent help call 111.

New Zealand National Poisons Centre 0800 764 766