Victorian coroners have thrown their weight behind calls for a drug testing trial in the state following the deaths of two men they believe unknowingly took synthetic substances.

Coroners Ingrid Giles and Simon McGregor published fresh recommendations, pleading for the government to consider a trial after their colleagues' calls for ongoing drug-checking services were effectively rejected.

Ms Giles investigated the death of a 38-year-old heroin user, who was found with a used syringe and several drugs in his system when he died - but no heroin.

Instead, toxicology tests found he took the potent opioid metonitazene, a member of the nitazene drug family.

Nitazenes are a group of strong synthetic opioids, up to 300 times stronger than morphine.

Ms Giles found that, at the time of the 38-year-old's death on December 5, 2022, he appeared to believe he was injecting heroin and was unaware of the dangerous synthetic opioid - a mistake other Victorians have made, with nitazenes involved in at least 16 overdose deaths in the state since 2021.

In some of those cases, the people who died were also unaware they were consuming nitazenes.

The other coroner, Mr McGregor, looked into the death of an 18-year-old man who died at the Royal Melbourne Hospital on April 27, 2023, five days after overdosing at the Dreamstate music festival at Flemington Racecourse.

People saw the 18-year-old take several MDMA tablets at the festival across three hours before he became distressed and had to be taken to hospital.

He ultimately died from an overdose of MDMA and methylone - a synthetic drug with stimulant effects - which Mr McGregor found the 18-year-old might have unknowingly consumed.

Methylone and other synthetic cathinones have been involved in at least 17 deaths in Victoria since 2013.

The coroners in both their decisions said while there was no guarantee either of the men would have used a drug testing service, it would have at least given them the opportunity to learn more about what they were actually taking.

Five Victorian coronial recommendations since 2021 have pushed for drug checking services in the state to reduce the risk of overdose deaths.

Ms Giles noted the success of pill testing trials in Canberra.

"While it cannot be said that (the 38-year-old's) death was preventable, it is my view that, given the tragic outcome, the potential for systemic improvement should be identified, considered, and pursued," the coroner said in her findings.

"The trial of a drug checking service represents a concrete opportunity to help to save the lives of people in the Victorian community and constitutes a mechanism for those who use drugs to be better informed of the unknown and potentially dangerous substances in those drugs."

The Victorian government was again urged to reassess its stance on pill testing at the weekend after a 23-year-old man died and two others were taken to hospital after suspected overdoses following the Pitch Music and Arts Festival.

The festival was subsequently cancelled because of dangerous heatwave conditions and extreme fire danger.

In January, Victorian Premier Jacinta Allan said she was seeking advice from the health department after at least 10 people were taken to hospital following suspected drug use at festivals.

"There are no current plans to change the policy setting on drug checking," she said at the time.

Harm Reduction Australia and Pill Testing Australia in November announced they formally offered to host a public health based pill testing trial at a festival of the government's choice at no cost to the state.