In recent years, we have now seen Substantial change In medicinal cannabis prescriptions, for products containing high levels of THC (tetrahydrocannabinol) – the ingredient that may cause drowsiness or high.
Now, our A new study This change presents some disadvantages, including products containing way more THC than the THC naturally present in hemp plants.
We found that greater than half of the cases of adversarial events involving unapproved medicinal cannabis products reported to the Therapeutic Goods Administration (TGA) were related to products with higher THC strengths.
For this group, psychiatric disorders – including anxiety, psychosis and paranoia – were probably the most commonly reported.
Released as our research The TGA is reviewing. Safety and Regulation of Unapproved Medicinal Cannabis Products. There are greater than 1,000 products which are legally available in Australia but haven’t been assessed for safety, quality and effectiveness by the TGA.
For high-potency THC products, there may be an increased risk of harm, particularly amongst certain vulnerable populations – reminiscent of youth and people with mental health conditions. A major concern.
What we did and what we found
We used Freedom of Information Requests. to the TGA to access greater than 1,100 separate adversarial events (sometimes called uncomfortable side effects) in greater than 600 cases reported from mid-2022 to May 2025.
We reviewed the sorts of medicinal cannabis products involved, including the most important sorts of cannabinoids within the products, the dosage forms (eg, plant or oil) and the most important sorts of adversarial events reported.
More than half (54%) of all adversarial event reports are related to products with high concentrations of THC.
These products can be found by prescription in Australia. They range from 13% to over 88% THC. In contrast, hemp plants can. Contains up to 30-35% THC.
Of all adversarial events reported, psychiatric disorders were the leading category, particularly for top THC products. Anxiety, psychosis and paranoia were probably the most common amongst them. We also observed 14 cases of suicidal thoughts, behavior and attempts.
However, simply because an adversarial event is reported, it doesn’t mean that it’s as a result of medicinal cannabis. But it’s a great sign, since psychiatric disorders are known adversarial events of THC.
Because some of these adversarial events are generally underreported, the increased frequency of those events is concerning, because the true rates are almost actually higher.
What about CBD? And breathable products?
Adverse events have also been reported for products containing cannabidiol (CBD). For CBD and combined CBD/THC oral oil products, these primarily involve the stomach or intestines. Here, adversarial events included nausea, vomiting and abdominal discomfort.
In general, and for products with higher THC potency, we also saw a rise in adversarial respiratory events, reminiscent of cough and shortness of breath. Preliminary research. It coincides with that. Increase in number of approvals For inhalation products.
Overall, adversarial events for all products and products with high THC potency include products which are commonly inhaled or smoked, reminiscent of dried flowers.
This is a giant change from us. Previous researchwhere most adversarial events involved products with roughly equal amounts of CBD and THC, and prescription approval was primarily Oral liquids.
In this First studynervous system disorders were a very powerful style of adversarial event, while psychiatric disorders at the moment are probably the most commonly reported.
We should be careful.
We are seeing this volume of great psychiatric adversarial events despite potentially significant underreporting. So it should take a better take a look at how these products are prescribed and monitored.
Prescriptions should be followed. Instructions published To protect patients. For example, TGA States Medicinal cannabis products containing THC are best avoided by patients with existing mood or anxiety disorders, or by individuals with a private or family history of great mental health concerns (reminiscent of psychosis or schizophrenia).
Smoking medicinal cannabis shouldn’t be advisable as a result of Known adverse health effects. as an alternative, TGA approved medical devices Medicinal cannabis is obtainable in pharmacies for vapor inhalation. The TGA says these devices include smoking and lower temperatures than production. Low toxicity.
What does this mean for patients?
If you utilize medicinal cannabis, your regular GP, who knows your health history and medications, is best placed to debate the potential advantages and risks.
All drugs, including medicinal cannabis, have potential uncomfortable side effects. These effects can range from mild to severe.
Talk to your trusted GP or pharmacist when you experience any adversarial events related to the medication. For severe effects, or when you feel really sick, call an ambulance or go to hospital.
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