With an increasing number of Australian women using weight loss drugs such as Ozempic, new guidelines and research have painted a broader picture of the impacts of the GLP-1-type medications.
Endorsed as a long-term treatment for obesity and the management of type 2 diabetes, the popularity of these weight loss medications has skyrocketed in Australia over the past five years.
Currently in Australia, the GLP-1 medications marketed include Ozempic (semaglutide), Wegovy (semaglutide), Saxenda (liraglutide), Trulicity (dulaglutide) and Mounjaro (tirzepatide).
Sales of GLP-1 medications have increased almost ten-fold from 57,941 units in May 2020 to 496.875 units in April 2025, according to a report led by researchers at the University of New South Wales (UNSW), which has yet to be peer reviewed. Overall, nearly 500,000 Australians are using these types of medications.
In August this year, the Therapeutic Goods Administration (TGA) approved semaglutide (marketed as Ozempic) for reducing the risk of kidney disease progression in patients with type 2 diabetes and chronic kidney disease. Before this, Ozempic was only approved in Australia for the treatment of type 2 diabetes, despite its popular off-label usage for weight loss.
Suicidal thoughts
On Monday, TGA issued a new safety warning over the Ozempic-style drugs, saying the research points to a potential risk of suicidal thoughts and behaviours when taking the drugs.
“Patients taking any of these medicines should tell their health professional if they experience new or worsening depression, suicidal thoughts or any unusual changes in mood or behaviour,” TGA said.
A 2024 study analysed the World Health Organization’s (WHO) global database of adverse reactions and found reports of suicidal thoughts were slightly higher than expected for semaglutide, even when compared to other diabetes drugs.
Reproductive health
There was also a warning issued on Monday by the TGA regarding the use of Mounjaro (tirzepatide) and its effects on oral contraception.
“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.”
In June this year, the UK Medicines and Healthcare products Regulatory Agency (MHRA) issued a warning to women taking weight loss drugs, urging them to use effective contraception while on the drugs, after dozens of reports of unintentional pregnancies.
MHRA also made clear that these weight loss drugs should not be taken during pregnancy, while trying to get pregnant, or during breastfeeding.
In Australia, women of reproductive age are increasingly being prescribed GLP-1 medications.
New research published by Flinders University in September this year showed that out of 18,010 women aged 18-49 who attended general practices between 2011 and 2022 and were prescribed GLP-1 medications, only 21 per cent reported using contraception, and 2.2 per cent of women became pregnant within six months of starting GLP-1 treatment.
Speaking to the findings, Chair of RACGP Specific Interests Antenatal and Postnatal Care, Dr Ka-Kiu Cheung told newsGP that “With the increasing use of GLP-1 receptor agonists for type 2 diabetes and weight management, it is important that GPs actively address reproductive health considerations in women of child-bearing age.”
Long-term treatments for obesity
Amid the concerns for mental health and reproductive health, the benefits for treating obesity and type 2 diabetes with GLP-1 medications remain present in global research.
On Tuesday, WHO released new guidelines conditionally recommending the GLP-1 medications as long-term treatments for obesity, calling on governments and health systems to ensure access remains universal.
Despite their increasing popularity for weight loss, WHO says the medications are projected to reach fewer than 10 per cent of those who could benefit from the drugs by 2030.
Published in the Journal of the American Medical Association (JAMA), the guidelines recommend that long-term GLP-1 therapies be used for weight management for adults with obesity alongside behavioural therapy, like physical activity, diet and regular counselling sessions.
Obesity remains a leading cause of chronic disease and premature death, with researchers pointing to the potential for GLP-1 medications to shift how obesity is treated by society as “a chronic relapsing disease requiring lifelong care”, rather than a “lifestyle condition”, says WHO.
In Australia, GLP-1 medications are currently only subsidised on the Pharmaceutical Benefits Scheme for treatment of type 2 diabetes in certain cases.
Many advocates, including the Royal Australian College of General Practitioners (RACGP), have been calling for the medication to be subsidised on the PBS for obesity as well, saying it would reduce health inequity and remove a significant cost barrier for many Australians.