Feature
Wegovy and Mounjaro are among the high-profile medicines with new product warnings, with the watchdog linking GLP-1 RAs to new side effects.
Around half a million GLP-1 RA units were sold each month in Australia in 2024–25 – a 10-fold increase in five years.
The Therapeutic Goods Administration (TGA) has issued new safety warnings for several high-profile GLP-1 receptor agonists, linking the medications to serious side effects.
On Monday, the TGA updated the product warnings for the ‘relatively new and high-profile’ class of medicines after they were linked to the potential risk of suicidal thoughts, with one also connected to reduced effectiveness of oral contraception.
The GLP-1 RAs currently marketed in Australia are:
- Semaglutide (sold as Ozempic and Wegovy)
- Liraglutide (sold as Saxenda)
- Dulaglutide (Trulicity)
- Tirzepatide (sold as Mounjaro)
As of 23 September, the TGA’s Database of Adverse Event Notifications includes 72 reports for suicidal ideation for the class of medications.
The medicines watchdog is now advising healthcare professionals to monitor patients for the emergence or worsening of depression, suicidal thoughts or behaviours, or any unusual changes in mood or behaviour.
‘Consider the benefits and risks for individual patients before initiating or continuing therapy in patients with suicidal thoughts or behaviours,’ it says.
While an investigation found available evidence is not sufficient to support an association between GLP-1 RAs and suicidal or self-harming behaviours, it said product information and consumer medicines information documents across the class were ‘inconsistent and should be harmonised’.
‘Updates should not imply a causal association, but reflect a class level awareness,’ the TGA said.
An additional TGA investigation into the potential for reduced effectiveness of oral contraception when first taking or increasing the dose of Mounjaro revealed an association ‘could not be ruled out’.
In response, and as a precautionary measure, product warnings for tirzepatide have also been updated to include further advice for patients using oral contraceptives.
‘Patients taking tirzepatide are advised to switch to a non-oral contraceptive or add a barrier method of contraception for four weeks after first taking the medicine and for four weeks after each increase in the dose,’ the TGA says.
‘None of the GLP-1 RAs should be used during pregnancy and individuals of childbearing potential are advised to use effective contraception during treatment with a GLP-1 RA.’
It comes just weeks after a new study found around half a million GLP-1 RA units were sold each month in Australia in 2024–25 – a 10-fold increase in five years.
‘In the year May 2024–April 2025, over six million units of GLP-1 RA were sold, predominantly semaglutide [63.3%] and tirzepatide [30.7%],’ it found.
‘In this period, GLP-1 RA use was estimated to cover 18 out of every 1000 Australians at a standard daily maintenance dose, with six out of every 1000 accessing these medicines privately.’
The TGA’s latest decision is in response to the United Kingdom’s Medicines and Healthcare products Regulatory Agency publishing guidance for GLP-1 medicines for weight loss and diabetes earlier this year.
‘We will continue to monitor the safety of GLP-1 RA medicines and will take appropriate regulatory action to address safety concerns when they are identified,’ the TGA concluded.
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Mounjaro Ozempic semaglutide TGA Therapeutic Goods Administration tirzepatide Wegovy
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