If you’ve been exploring every avenue for additional weight loss support in Australia, you might have heard about injectable medications. While certainly not magic bullets, they could be a powerful weight management tool when used under proper medical supervision alongside lifestyle changes.
Let’s explore five common injectable weight loss medications available in the Great Southern Land: Ozempic, Wegovy, Saxenda, Trulicity, and Mounjaro. Learn what they are, how they work, and most importantly, whether they might be appropriate for your health journey.
The Science Behind the “Skinny Jab” Revolution
“Skinny jab” is a popular and informal term for injectable medications used for weight loss [1]. Before diving into each specific medication, it’s important to understand the breakthrough science surrounding them. Most of these medications belong to a class called GLP-1 receptor agonists (GLP-1 RAs) – but what does that actually mean?
GLP-1 stands for glucagon-like peptide-1. According to research [2], it’s a hormone naturally produced in the gut that plays a crucial role in regulating appetite and blood sugar (by stimulating insulin release and lowering glucagon secretion). These medications mimic this natural hormone, essentially amplifying its effects.
They mostly help with weight loss by [2]:
- Slowing digestion: They slow down gastric emptying, which means food stays in your stomach longer. This helps you feel fuller for a longer period after eating.
- Signaling fullness to your brain: As the levels of these hormone-mimicking molecules rise, they travel to your brain, sending strong signals that you’re full and satisfied. This helps reduce overall appetite and cravings.
Think of it as your body’s natural “I’m full” signal being amplified and extended. Unlike crash diets that rely on willpower alone, these medications work with your biology to reduce appetite and cravings.
Trying to lose weight but unsure about your calorie needs? Our Weight Loss Calculator helps you discover your ideal daily calorie intake for sustainable results.
A newer class, referred to as dual agonists, like Mounjaro, takes this a step further by mimicking both GLP-1 and another hormone, glucose-dependent insulinotropic polypeptide (GIP), which could lead to even more pronounced effects on weight loss and blood sugar control [2].
Now, let’s explore each medication in detail.
1. Ozempic (Semaglutide)
Ozempic, containing the active ingredient semaglutide, is a widely recognised medication. While initially approved in Australia for the management of type 2 diabetes, its significant weight-loss effects have led to its off-label use for obesity [3].
Benefits [2]:
- Effective in significantly reducing blood sugar levels in type 2 diabetes.
- Could lead to significant weight loss.
- May reduce the risk of major cardiovascular events in adults with type 2 diabetes and cardiovascular disease.
Potential side effects: Common side effects include nausea, vomiting, diarrhoea, constipation, and abdominal pain [2]. More serious, though rare, side effects may include pancreatitis, gallbladder disease, and a boxed warning [4] for thyroid tumours (observed in animal studies).
Australian availability and considerations [5]: Ozempic is a prescription-only medication. While popular for weight loss, its high demand for off-label use has unfortunately led to ongoing shortages, impacting access for those with type 2 diabetes who genuinely need it. It is not officially approved for weight loss in Australia.
Feature | Ozempic (Semaglutide) |
Primary use | Type 2 Diabetes (off-label for weight loss in Australia) |
Active ingredient | Semaglutide |
Administration | Once weekly subcutaneous injection |
Approval in Australia | Approved for type 2 diabetes |
2. Wegovy (Semaglutide)
Wegovy, also containing semaglutide, is specifically approved in Australia for chronic weight management in adults who are obese or overweight with at least one weight-related comorbidity [4,5]. This is a key distinction from Ozempic, despite sharing the same active ingredient.
Benefits [2]:
- Approved for chronic weight management in eligible individuals.
- May lead to significant weight loss.
- May reduce the risk of serious heart problems in adults with heart disease and obesity or overweight.
Potential side effects [2]: Common side effects are largely gastrointestinal, including mild to moderate nausea, diarrhoea, vomiting, constipation, and abdominal pain.
Australian availability and considerations [5]: Wegovy is Therapeutic Goods Administration (TGA)-approved for weight management. It requires a prescription and is typically used in conjunction with a reduced-calorie diet and increased physical activity.
Feature | Wegovy (Semaglutide) |
Primary use | Chronic weight management |
Active ingredient | Semaglutide |
Administration | Once weekly subcutaneous injection |
Approval in Australia | Approved for weight management |
3. Saxenda (Liraglutide)
Saxenda, with the active ingredient liraglutide, is another injectable medication approved in Australia for weight management [7,8]. Unlike Ozempic and Wegovy which are once-weekly, Saxenda is a daily injection [2,6].
Benefits [6,7]: Approved for weight loss and long-term weight management in adults with obesity or overweight with comorbidities, and some children.
Potential side effects [6,7]: Common side effects include nausea (most common), vomiting, abdominal pain, constipation, diarrhoea, and headache. Serious side effects may include acute pancreatitis, gallbladder disease, increased heart rate, kidney problems, and a boxed warning for thyroid cancer (based on animal studies).
Australian availability and considerations [7,8]: Saxenda is approved by the TGA for weight management. It is a prescription-only medication, and its use is typically alongside a reduced-calorie diet and increased physical activity.
Feature | Saxenda (Liraglutide) |
Primary Use | Weight loss and long-term weight management |
Active Ingredient | Liraglutide |
Administration | Once daily subcutaneous injection |
Approval in Australia | Approved for weight management |
4. Trulicity (Dulaglutide)
Trulicity, containing dulaglutide, is primarily approved in Australia for the treatment of type 2 diabetes. While it may lead to some weight loss, it is not specifically indicated for weight management in the same way as Wegovy or Saxenda [2,8].
Benefits [2]:
- May improve blood sugar control in adults with type 2 diabetes.
- Could reduce the risk of major adverse cardiovascular events in patients with type 2 diabetes.
- May contribute to modest weight loss.
Potential side effects [2]: Very common side effects include nausea, diarrhoea, abdominal pain, and vomiting, which tend to be more frequent when first starting the medication. Serious side effects may include severe low blood sugar (especially when used with insulin or sulfonylurea), dehydration, gallbladder issues, and acute pancreatitis.
Australian availability and considerations [9]: Trulicity is a prescription-only medication, primarily subsidised through the Pharmaceutical Benefits Scheme (PBS) for type 2 diabetes. Its use for weight loss alone is generally off-label.
Feature | Trulicity (Dulaglutide) |
Primary use | Type 2 diabetes (with potential modest weight loss) |
Active ingredient | Dulaglutide |
Administration | Once weekly subcutaneous injection |
Approval in Australia | Approved for type 2 diabetes |
5. Mounjaro (Tirzepatide)
Mounjaro, with the active ingredient tirzepatide, is a newer and distinct medication. While Ozempic and Trulicity mimic the effect of one hormone, Mounjaro is a dual agonist, meaning it mimics two hormones: GLP-1 and GIP [2].
Benefits [2]:
- Significantly highly effective for blood sugar control in type 2 diabetes.
- Demonstrated significant weight loss, potentially more than GLP-1 monotherapy.
- Recently approved for sleep apnoea in adults with obesity [10].
- May improve cardiovascular risk factors.
Potential side effects [2]: Common side effects may include nausea, diarrhoea, loss of appetite, vomiting, constipation, and abdominal pain. Serious side effects could include severe digestive problems, acute kidney injury (due to dehydration from severe GI upset), gallbladder problems, pancreatitis, and a boxed warning for thyroid cancer.
Australian availability and considerations [10]: Mounjaro is approved for type 2 diabetes and recently for sleep apnea in obese adults. It is currently not subsidised under the PBS for weight management and is available by private prescription, which could be costly.
Feature | Mounjaro (Tirzepatide) |
Primary use | Type 2 Diabetes; Obstructive Sleep Apnea with Obesity (with significant weight loss) |
Active ingredient | Tirzepatide (Dual GLP-1 and GIP agonist) |
Administration | Once weekly subcutaneous injection |
Approval in australia | Approved for obstructive sleep apnea in obese adults; strong evidence for weight loss |
Important Considerations for All Injectable Weight Loss Medications
Injectable weight loss medications, while offering a promising avenue for many, come with a set of important considerations that prospective users should be fully aware of:
- Prescription only: All these medications require a prescription from a qualified healthcare professional in Australia. Self-medicating is strongly discouraged and could be dangerous.
- Not a magic bullet: These medications are most effective when used in conjunction with comprehensive lifestyle changes, including a reduced-calorie diet and increased physical activity.
- Individualised treatment: The choice of medication, dosage, and suitability will depend on your individual health profile, medical history, existing conditions (like type 2 diabetes), and potential side effects. Always consult with your doctor.
- Potential side effects: While generally well-tolerated, gastrointestinal side effects are common. Serious side effects, though rare, may occur. It’s crucial to discuss these with your doctor and report any concerning symptoms.
- Cost and access: While some medications might be subsidised for specific conditions (like type 2 diabetes) under the PBS, their use purely for weight loss might not be covered, leading to significant out-of-pocket expenses. Shortages may also impact accessibility.
Read more: Weight Loss Injections Cost in Australia >>
- Ongoing monitoring: Regular follow-ups with your doctor are essential to monitor your progress, manage side effects, and adjust your treatment plan as needed.
Wrapping It Up!
The availability of injectable weight loss medications in Australia marks a significant step forward in chronic weight management. They offer a promising avenue for individuals struggling with weight loss. However, they are powerful tools that require careful consideration, medical supervision, and a commitment to comprehensive lifestyle changes.
Before starting any weight loss medication, always consult with your healthcare provider to determine if you’re a suitable candidate and which option might work best for your individual circumstances. Remember, sustainable weight management is a journey, not a destination, and these medications are just one part of a comprehensive approach to better health.
References:
- Women on “skinny jabs” must use effective contraception, MHRA urges in latest guidance. GOV.UK. Published June 4, 2025. https://www.gov.uk/government/news/women-on-skinny-jabs-must-use-effective-contraception-mhra-urges-in-latest-guidance
- Collins L, Costello RA. Glucagon-like peptide-1 receptor agonists. PubMed. Published February 29, 2024. https://www.ncbi.nlm.nih.gov/books/NBK551568/
- Kanellis C, Williams K, Holt DQ, et al. The role of GLP‐1 receptor agonists in the management of obesity: risks and opportunities for the Australian health care system. The Medical Journal of Australia. Published online January 9, 2025. doi:https://doi.org/10.5694/mja2.52582
- Semaglutide (Ozempic®, Wegovy®). https://www.hhs.texas.gov/sites/default/files/documents/semaglutide-ozempic-monograph.pdf
- Goods T. Ozempic (semaglutide) supply information. Therapeutic Goods Administration (TGA). Published December 8, 2022. https://www.tga.gov.au/safety/shortages/information-about-major-medicine-shortages/ozempic-semaglutide-supply-information
- Cerillo JL, Parmar M. Liraglutide. Nih.gov. Published October 6, 2024. https://www.ncbi.nlm.nih.gov/books/NBK608007/
- Australian Public Assessment Report for Liraglutide. https://www.tga.gov.au/sites/default/files/auspar-liraglutide-190429.pdf
- Goods T. New diabetes and weight loss medicines. Therapeutic Goods Administration (TGA). Published June 3, 2025. https://www.tga.gov.au/news/safety-alerts/new-diabetes-and-weight-loss-medicines
- Goods T. About the Trulicity (dulaglutide) shortage. Therapeutic Goods Administration (TGA). Published December 12, 2022. https://www.tga.gov.au/safety/shortages/information-about-major-medicine-shortages/about-trulicity-dulaglutide-shortage
- newsGP – Mounjaro approved to treat sleep apnoea. NewsGP. Published 2025. https://www1.racgp.org.au/newsgp/clinical/mounjaro-approved-to-treat-sleep-apnoea
