You’ve probably heard the names of Ozempic, Wegovy, or Mounjaro floating around lately. They’re no longer just “that American injection” making headlines, as they’re now widely used weight loss medications in Australia. With so much talk circulating, it can be tricky to separate fact from hype. So, let’s break it down and take a closer look at what these medications are, how they work, and what they’re used for, from an evidence-based perspective.
So, what are they?
These are part of a newer class of medications called GLP-1 or dual GIP/GLP-1 receptor agonists. They were originally designed to help manage Type 2 diabetes but have also become well-known for their effect on weight.
The GLP-1 medications currently marketed in Australia include:
- Ozempic (semaglutide): for diabetes
- Trulicity (dulaglutide): for diabetes
- Victoza (liraglutide): for diabetes
- Saxenda (liraglutide): for weight management
- Wegovy (semaglutide): for weight management
The dual GIP/GLP-1 medications include:
- Mounjaro (tirzepatide): for both diabetes and weight management
(All are approved by the Therapeutic Goods Administration (TGA) – Australia’s medication regulator).(1)
How do they work?
GLP-1 medications mimic a natural hormone called GLP-1 (glucagon-like peptide-1), released by the gut after eating. This can:
- Slow stomach emptying
- Enhance satiety (fullness)
- Lower appetite and food cravings
- Improve how your body uses insulin
Mounjaro goes a step further by also working with the hormone GIP (glucose-dependent insulinotropic polypeptide). This can improve insulin function and contribute to reductions in visceral and organ fat.(2)
What most people notice is:
- Feeling full sooner
- Less interest in food
- Fewer cravings and less “food noise”
However, they’re not magic injections. Food choices, movement, sleep, and habits still play a huge role.
What are the trade-offs?
As with any medication, side effects are possible. The most common side effects are gut-related, including nausea, vomiting, diarrhoea, and constipation. These are often mild, but for some people, they can make it difficult to continue treatment.
Less common, but more serious risks include pancreatitis and gallbladder issues. It’s also important to note that there is still limited data on the safety of these medications in people without diabetes. (3,4)
Another consideration is what happens when treatment stops. Evidence shows that after stopping treatment, even with lifestyle intervention, people can regain a significant portion of the weight lost. For example, participants in a trial of once-weekly semaglutide (like Wegovy and Ozempic) regained around two-thirds of their prior weight loss within a year of discontinuing the medication. (5)
Some of the reasons why this occurs include:
- Hunger hormones return to usual levels, resulting in overeating or difficulty feeling full on usual portions of food.
- Food cravings and “food noise” return, resulting in unhelpful or impulsive snacking behaviours, particularly those of energy-dense snack foods
- Slower metabolism as a result of losing weight (in particular muscle mass), resulting in less efficient use of calories to fuel the body, making weight regain easier.
- Difficulty in sustaining healthier eating habits adopted during treatment
In short, weight regain is normal and to be excepted when treatment stops, as such these medications are most effective when used long-term. Additionally, building skills around managing the behaviours that may lead to weight regain is essential regardless of ongoing treatment or when considering stopping treatment.
Where does a dietitian come in?
These medications, like many strategies to lose weight, are a tool. However, without the right guidance and support, they can also lead to problems like undereating, missing key nutrients, or developing unhelpful eating behaviours. This might look like skipping meals, loss of appetite awareness, restrictive eating, or binge-restrict cycles. That’s where dietitians can help.
We can support you to:
- Build an eating pattern that gives your body enough fuel and protein for maintaining health and metabolism (muscle mass) across the day
- Prevent malnutrition and micronutrient deficiencies
- Support healthy digestion, hydration, and appetite regulation
- Distinguish between true hunger vs habit-driven/impulsive eating
- Learn practical strategies for addressing unhelpful eating behaviours
- Build sustainable healthy eating habits beyond reduced food intake and appetite suppression
A weight neutral perspective
In a weight-neutral practice, we focus on overall health, not just the number on the scales. Success and health are measured by many things like energy levels, digestion, relationship with food, mental health, and long-term habits.
Appetite, hunger and cravings are normal biological signals, not problems to eliminate. Over time, they’re something to understand and work with, not against. Without support, it’s easy to slip into unsustainable eating patterns, so the focus shifts toward building consistent, supportive habits rather than chasing short-term weight changes.
It’s also important to recognise that the scale does not tell the full story. Weight may plateau even while body composition and metabolic health improve. Maintaining or increasing muscle mass is often a more meaningful marker of progress than weight alone.
Other ways we may see progress outside of weight include:
- Regular, adequate and balanced eating
- Reduced binge-restrict cycles or chaotic eating patterns
- Improved awareness of hunger and fullness cues (and not fearing them)
- Consistency with movement
- Incorporating resistance training to support strength and muscle mass
- Building a more trusting relationship with food
The aim is not perfection and quick results, but rather steady, sustainable behaviour change that supports long-term health and wellbeing.
If you are looking for holistic support while using a weight loss medication, get in touch with our amazing team of dietitians or book an appointment today!
References
- Therapeutic Goods Administration (TGA). Medicines containing GLP-1 and dual GIP/GLP-1 receptor agonists. Published June 3, 2025. Accessed February 24, 2026. https://www.tga.gov.au/news/safety-updates/medicines-containing-glp-1-and-dual-gipglp-1-receptor-agonists
- Cariou B, Linge J, Neeland IJ, et al. Effect of tirzepatide on body fat distribution pattern in people with type 2 diabetes. Diabetes Obes Metab. 2024;26(6):2446-2455. doi:10.1111/dom.15566
- 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. Med J Aust. 2025;222(3):118-121. doi:10.5694/mja2.52582
- The Royal Australian College of General Practitioners. Glucagon-like peptide-1 receptor agonists for weight management. Aust J Gen Pract. 2025;54(4). Accessed February 24, 2026. https://www1.racgp.org.au/ajgp/2025/april/glucagon-like-peptide-1-receptor-agonists-for-weig
- Wilding JPH, Batterham RL, Davies M, et al; STEP 1 Study Group. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes Obes Metab. 2022;24(8):1553-1564. doi:10.1111/dom.14725
