Three years of official monitoring data deliver an uncomfortable verdict. Medicinal cannabis harm in Australia keeps rising. The system that created it shows no sign of slowing down.

Between mid 2022 and mid 2025, the Therapeutic Goods Administration logged 614 adverse event reports linked to medicinal cannabis. Half involved category 5 products. These are the high strength dried flower and concentrated extracts that can legally contain up to 88 per cent THC, since Australia sets no upper limit at all. The reports include psychosis, cannabis hyperemesis syndrome and suicidal behaviour. A further 27 cases have already reached the TGA voluntarily in 2026 alone.

None of this appears to be slowing prescribing. A new review from Monash University has found that doctors are routinely prescribing cannabis as medicine at THC concentrations up to four times higher than anything ever tested in a clinical trial. More than 1,000 medicinal cannabis products are currently available in Australia. Only two have been through the TGA’s full evaluation process for quality, safety and efficacy.

The Scale of Medicinal Cannabis Harm in the Numbers

Professor Suzanne Nielsen from the Monash Addiction Research Centre co-authored the review. She says there is a genuine mismatch between the evidence base and what patients actually receive. Her team found that randomised trials had only ever properly tested products containing up to 22 per cent THC. Yet category 5 products now make up half of all approvals, mostly for chronic pain and anxiety.

That gap matters more than it might first appear. Research finds cannabis no more effective than a placebo for anxiety. Even for chronic pain, researchers describe the supporting evidence as low quality. Nielsen wants the regulator to cap THC concentration nearer the levels tested in trials, rather than the levels the plant can naturally reach.

Profit Before Patients

A 2025 review by the Australian Health Practitioner Regulation Agency uncovered a prescribing culture. It looks less like medicine and more like a sales funnel. Some practitioners issued more than 10,000 prescriptions for high strength THC products within six months. Some consultations reportedly lasted only seconds. This is medicinal cannabis harm in its most direct form, with profit incentives overriding clinical judgement.

The president of the Royal Australian College of General Practitioners, Dr Michael Wright, has been blunt about what is driving this. Clinics must not prioritise profits over patient safety, he says. Online cannabis operations run purely as businesses create conflicts of interest. Those conflicts are now showing up in hospital psychosis presentations. Effective, evidence-based treatments already exist for chronic pain and insomnia, he points out. There is no clinical reason for THC concentrations to sit this high.

A Model Built on Consultation Theatre

None of this happened by accident. Victoria pushed the regulatory door open back in 2014. Its Law Reform Commission ran a consultation on medicinal cannabis that year. The process drew on just nine public hearings and 99 submissions, most from existing cannabis users. That thin evidence base became the foundation for legislation. Victoria then launched its own scheme at a reported cost of 35,000 dollars per child. More than a third of paediatric patients dropped out once the treatment failed to work.

Western Australia followed a similar path in 2017. The state legalised cannabis as medicine that year. Not one of its 10,000 plus doctors applied to prescribe it for months afterwards. Contrast that hesitation with Epidiolex. It is the only cannabis derived medicine to go through a full decade long clinical trial process before approval. Since 1997, researchers have published more than 11,000 studies on THC alone worldwide. The cost approaches five billion US dollars. The net clinical gain beyond already available treatments remains modest.

Still No Brakes

What makes the current moment different is that this is no longer a fringe concern. A peak professional body, a leading university research centre and the medical regulator have all reached the same conclusion. Each used its own data. Each covered roughly the same three year window. Yet category 5 products keep expanding their share of approvals. THC concentration remains uncapped. Telehealth clinics keep growing.

Three years of adverse event data have not been enough to trigger a rethink. Medicinal cannabis harm keeps accumulating regardless. Concentration limits, proper evaluation and genuine patient assessment need to become the standard rather than the exception. Until that happens, the gap between what cannabis as medicine promises and what it is actually delivering looks set to keep widening.

Sources:

‘Prioritising profit’: Australians regularly prescribed medicinal cannabis with very high THC levels

Failing Mental Health and ‘Vote for Medicine’ Models: Cannabis Conundrum Grows