An overview of how GLP-1 receptor agonists work, what the evidence shows, how the prescription pathway works in Australia, and the important considerations before starting treatment.
Important: This page is general educational information only and does not constitute medical advice. GLP-1 receptor agonists are prescription-only medicines in Australia. Individual suitability varies and there are specific contraindications. Always consult a qualified, AHPRA-registered medical practitioner before making any decisions about your health.
GLP-1 receptor agonists have become among the most discussed medicines in Australia following the broader awareness of semaglutide and tirzepatide for weight management. This article covers what these medicines are, what the clinical evidence shows, how the prescription pathway works in Australia, and the important evidence limitations and contraindications that should be understood before any decision is made.
GLP-1 receptor agonists are a class of medicines that activate glucagon-like peptide-1 receptors. GLP-1 is a naturally occurring hormone involved in glucose regulation, appetite signalling, and gastric emptying. Medicines in this class reduce appetite, slow gastric emptying, and improve glucose regulation by activating these receptors.
Semaglutide (the active ingredient in Ozempic and Wegovy) and tirzepatide (the active ingredient in Mounjaro) are the two most clinically studied compounds in this class for weight management. Both are TGA-registered medicines in Australia, meaning they have undergone TGA evaluation for safety, quality and effectiveness for their approved indications.
Large-scale clinical trials have examined semaglutide and tirzepatide for weight management in adults with obesity or weight-related conditions. These trials have demonstrated substantial average reductions in body weight compared to placebo over the trial periods studied, and this evidence base is more developed than most medicines in the metabolic health space.
The evidence also shows consistent findings about what happens when treatment stops. Studies demonstrate that weight regain occurs after discontinuing GLP-1 receptor agonist treatment, with participants returning toward pre-treatment weight over time. This is an important aspect of the evidence that should be understood before starting treatment, and is one of the reasons why clinical oversight throughout a treatment period matters.
Contraindications: GLP-1 receptor agonists are not appropriate for everyone. Known contraindications include personal or family history of medullary thyroid carcinoma, Multiple Endocrine Neoplasia syndrome type 2, and history of pancreatitis, among others. A qualified medical practitioner must assess individual history before prescribing. This is not a medicine to access without a proper clinical assessment.
The most commonly reported side effects in clinical trials are gastrointestinal, including nausea, vomiting, diarrhoea and constipation. These are typically most pronounced during dose escalation and often improve over time. More serious adverse events have been reported in post-marketing surveillance, and ongoing monitoring of safety data continues as these medicines are used in broader populations.
As with any prescription medicine, the decision to use a GLP-1 receptor agonist should be made in consultation with a qualified doctor who can assess individual circumstances, review current medications for interactions, identify contraindications, and monitor for adverse responses during treatment.
GLP-1 receptor agonists are Schedule 4 prescription-only medicines in Australia. A prescription requires assessment by an AHPRA-registered medical practitioner who reviews the individual's health history, current medications, weight and metabolic markers, and any contraindications before prescribing.
TGA-registered GLP-1 products including Wegovy and Mounjaro are available through Australian pharmacies with a valid prescription. Compounding pharmacy versions of these compounds are also accessible through licensed Australian compounding pharmacies against a valid prescription. Both pathways require a valid prescription from an AHPRA-registered doctor. The compounding pathway does not provide a shortcut around the prescription requirement or the need for a proper medical assessment.
GLP-1 and long-term use: The clinical evidence indicates that GLP-1 receptor agonists work while being taken, with weight returning when treatment stops. This characteristic has implications for how these medicines are considered in the context of long-term weight management. A doctor assessing individual circumstances is best placed to discuss what this means for any specific person.
For authoritative information on GLP-1 medicines in Australia, the TGA's published product information and the Therapeutic Goods Register are the relevant official sources.
The following official sources provide authoritative information on GLP-1 receptor agonists and weight management medicines in Australia:
This article is general educational information only. Nothing on this page constitutes medical advice or a recommendation to seek, use or purchase any GLP-1 medicine. GLP-1 receptor agonists are prescription-only medicines with specific contraindications and risks. Always consult a qualified, AHPRA-registered medical practitioner before making decisions about your health. For the TGA's current information on these medicines, visit www.tga.gov.au.