We’ve all seen the rise of GLP-1 weight loss medications like Ozempic in Australia, the UK and US. Whether you like them or not they can help people to lose significant amounts of weight and keep it off. Our in-house dietitian Lily ‘Lentil’ gives us the latest on weight loss medications in New Zealand and why your diet still matters.
The buzz
The world of weight loss got a big shake up when Ozempic came on the scene. The reason? Research has consistently shown that this class of medications, when taken consistently can achieve around 10-15% weight loss which is clinically significant and means they are effective (1,2)!
What is Semaglutide?
Semaglutide is the main ingredient in these weight loss and diabetes medications, and they belong to a class of drugs called Glucagon-like Peptide (GLP-1) medications. These medications (i.e. Ozempic) were originally developed for lowering blood glucose levels to manage type 2 diabetes. However, now versions of the medication (i.e. Wegovy) have since been developed to support weight loss.
How do these medications work?
Medications like Wegovy and Ozempic bind to GLP-1 receptors in the body, mimicking the effects of the GLP-1 hormone naturally produced in the gut but for a longer period of time.
There are three ways that they work:
- Lowering blood sugar: stimulating the secretion of insulin after a meal which helps to lower blood sugar levels.
- Controlling appetite: slowing down digestion which helps you to feel full for longer.
- Weight loss: reducing appetite and increasing the feeling of satiety which makes it easier to manage cravings, eat less and feel full for longer periods.
Are these medications a magic pill?
No matter what medication you are taking they shouldn’t be thought of as a “quick fix” or easy route for weight loss! Any medication is designed to be used alongside lifestyle changes for long-term weight loss.
In fact, the quality of your diet becomes even more important when you are reducing your food intake whether that’s through less food across the day or smaller portions. A diet rich in whole foods such as vegetables, fruits, lean proteins, legumes and fibre-containing foods like whole grains provides the essential vitamins, minerals, and nutrients your body needs to function optimally. Adequate protein is essential to preserve lean muscle mass during weight loss, ensuring that your body burns fat rather than breaking down valuable muscle tissue.
What medications are available in NZ?
Over the past couple of years GLP-1 medications have received a lot of media and social media attention. A GLP-1 medication called Saxender has been available in New Zealand for some time and Wegovy was approved in 2025 and is able to be prescribed since 1 July 2025 (3).
The weight loss medications currently available in NZ include* (4):
- Semaglutide (WeGovy): belongs to the group of GLP-1 medications and is administered by a weekly injection.
- Liraglutide (Saxenda): belongs to the group of GLP-1 medications and is administered by a daily injection.
- Orlistat (Xenical): belongs to a group of medicines called lipase inhibitors which prevent the absorption of dietary fat in your body.
- Phentermine (Duromine): an appetite suppressant that affects the part of your brain that controls appetite making you feel less hungry.
- Naltrexone/buproprion (Contrave): works on areas on the brain involved in the control of food intake and energy use
*Note all these medications require a prescription and you must meet certain referral criteria
Of these available medications, Semaglutide (Wegovy) is the most effective and achieves an average weight loss of around 5-18% however people may experience gastrointestinal side effects particularly in the first 8 weeks (5,6). Older weight loss medications i.e. Orlistat, Phentermine may not be as effective at achieving substantial weight reduction and many have side effects (7).
The elephant in the room
Some weight loss medications may be funded for health conditions like diabetes, but most are unfunded which means you have to pay for them. They vary in price, costing between $100 and $500 per month (4).
The other thing to consider is how well you tolerate the medication and any side effects. Ozempic and Wegovy can cause gastrointestinal issues like nausea, diarrhea, constipation and reflux especially during the initial phase (1). Other weight loss medications all have varying side effects and risks to your health.
What about the long-term
Different people respond differently to weight loss medicines and other approaches like weight loss surgery. Your GP, dietitian or specialist is the best person to advise whether weight loss medications are safe and suitable for you over the long term.
Studies have shown that people who stop using Wegovy/Ozempic more often than not regain the weight they have lost (8). It’s estimated that around 10% of people will be able to maintain the weight they have lost when discontinuing the medication. This means taking a holistic approach to managing weight is important where all areas of lifestyle including a gut friendly diet, adequate sleep, regular physical activity and stress management are addressed in a way that is realistic and relevant to you. A diet that supports gut health is particularly important because the gut microbiome has a key role in how you use the nutrients from the food you eat and is also involved in food cravings, hunger and appetite.
The common factors for long-term weight maintenance post medication include a calorie-controlled diet, regular physical activity (300-360 minutes of moderate activity a week) and regular weigh-ins and monitoring.
A tool in the toolbox
At the end of the day, we should be thinking of weight loss medications as one tool in the toolbox!
To truly harness their benefits, they need to be paired with a balanced diet that hero’s nutrient-rich and gut-friendly foods. This will enhance the effectiveness of the medication and help you to achieve your long-term weight and health-related goals. It will also ensure that nutrition needs are meet and helps to prevent other diet-related health problems.
Before starting any medication, consider whether the investment is worthwhile given your personal weight loss goals and health needs.
It’s always important to obtain advice from your healthcare provider on the benefits, risks, and side effects of any medication you are intending to take.
References
(1) Ryan, D.H., Lingvay, I., Deanfield, J. et al. Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial. Nat Med 30, 2049–2057 (2024).
(2) Ghusn W, De la Rosa A, Sacoto D, Cifuentes L, Campos A, Feris F, Hurtado MD, Acosta A. Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity. JAMA Netw Open. 2022 Sep 1;5(9):e2231982.
(3) PHARMAC website. Semaglutide (Wegovy) for weight loss. Access 1 July 2025. www.pharmac.govt.nz/news-and-resources/news/semaglutide-wegovy-ozempic
(4) Healthify website. Common Questions about Weight Loss Medications. Accessed online 21 November 2024. https://healthify.nz/medicines-a-z/w/weight-loss-medicines/
(5) Zhang P, Liu Y, Ren Y, Bai J, Zhang G, Cui Y. The efficacy and safety of liraglutide in the obese, non-diabetic individuals: a systematic review and meta-analysis. Afr Health Sci. 2019 Sep;19(3):2591-2599. doi: 10.4314/ahs.v19i3.35.
(6) Moiz, Areesha et al. Long-Term Efficacy and Safety of Once-Weekly Semaglutide for Weight Loss in Patients Without Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. American Journal of Cardiology, Volume 222, 121 – 130
(7) Mozaffarian D et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity (Silver Spring). 2025 May 30.
(8) Rubino D, Abrahamsson N, Davies M, et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial. JAMA. 2021;325(14):1414–1425.
