Two deadly pills were picked up by pill testers at a music festival in Canberra yesterday.

The Australian-first trial at Groovin the Moo saw 128 festival-goers get their drugs analysed by chemical analysts for free at the pill testing tents.

Around half of the 85 sample of illicit drugs tested were not “pure”, pill testers have confirmed. "Other” substances found included paint, toothpaste and lactose.

128 festival-goers had their illicit drugs tested at the Groovin the Moo festival in Canberra yesterday. (9NEWS) (9NEWS)

But most concerning were two pills that contained deadly chemicals, including the “absolutely lethal” N-Ethylpentylone (ephylone), which has caused a number of overdoses around the world.

STA-SAFE member and emergency doctor David Caldicott told ABC Radio Canberra that the two deadly substances were found inside clear capsules and were disposed of immediately.

He said the two people who bought the capsules were “extremely grateful” that the substances were found.

NSW Greens MP Dr Mehreen Faruqi said that the trial proves that pill testing saves lives.

“We have just had a successful trial in Canberra that shows pill testing is safe, effective, popular and most importantly saves lives,” she said in a statement this afternoon.

Two deadly pills were found, as well as a host of other "unpure" drugs. (9NEWS) (9NEWS)

“The reality is people take drugs whether the NSW Government likes it or not. They need to get out of the way to allow experts to get on with the job of keeping people safe.”

There was clear evidence that the government’s current “punitive, heavy-handed approach” to drug use wasn’t working, she added.

The Greens have called for the pill testing initiative to be rolled out across New South Wales.

Many festival-goers told experts they would either reconsider taking or take less of the

Drug rehabilitation and harm minimisation organisation, the Ted Noffs Foundation, said the results of yesterday’s trial showed that pill testing was a critical in reducing the harm of illicit drugs.

Greens NSW MP and Drugs & Harm Minimisation Spokesperson, Dr Mehreen Faruqi MLC, wants pill testing rolled out at festivals across NSW. (AAP) (AAP)

Pill testing already takes place in about 20 countries across the world. (AAP) (AAP)

Many festival-goers told experts they would either reconsider taking the illicit substances they had bounght on the black market or take less of them.

Several threw away their drugs after getting back the results of the testing and finding the drugs weren’t what they expected.

“We’ve just taken a big step towards taking back control of the dangerous black market in drugs in order to keep our kids safe," Ted Noffs Foundation CEO Matt Noffs said.

Mr Noffs said that the instigators of the pill testing initiative will all be “recognised in years to come as having helped save lives”.