Prescription weight loss medications
Are weight-loss medications worth the hype?
Medications being used for weight loss, like Wegovy and Ozempic, have been making headlines and showing up a lot on social media. But, what do we actually know about these drugs? Do they live up to their hype? And, more importantly, how safe are they?
We spoke with nib Medical Advisor, Dr Hamish Black, to break down not just if they work, but how these medications work, their potential risks and benefits, and whether they might (or might not) be a good fit for you.
What are weight loss medications?
Weight loss medications are designed to lower your weight in a variety of ways. They are always recommended to be used alongside healthy lifestyle changes, such as getting enough exercise, opens in a new tab and eating nutritious, opens in a new tab foods.
"’Weight loss medications’ are products that help you lose weight by decreasing appetite or affecting the way your body absorbs food,’ explains Hamish.
The Therapeutic Goods Administration, opens in a new tab (TGA), categorises products based on their weight loss claim into one of two types:
Complementary medicines
You probably know these as supplements. You can find them in health food stores, supermarkets, and pharmacies without needing a prescription. They usually contain natural ingredients like herbs, fibre, vitamins, and minerals, opens in a new tab. These products are regulated by the TGA and are marked with an AUST L number on their packaging, indicating they are considered low risk.
Prescription medication
You can only use these medications with a prescription from your doctor. TGA-approved prescription medications are marked with an AUST R number on their label.
Which weight loss drugs are approved?
Five medications, opens in a new tab are currently approved in Australia to help manage obesity, and there are more on the way. The treatment options are growing fast, with new drugs being developed to help tackle obesity and its related health issues.
However, some weight-loss medications are used off-label, meaning they’re prescribed by doctors for a purpose that isn’t officially approved by the TGA. This usually happens when other treatments haven’t worked.
Ozempic is a great example of one of these medications. It’s primarily approved for treating type 2 diabetes, opens in a new tab, not weight loss. Similarly, Topiramate, opens in a new tab, which is approved for epilepsy, is also used off-label for weight loss.
How do prescription weight loss drugs work?
“Weight loss medications work in various ways” explains Hamish. “Some drugs suppress your appetite by tricking your brain into thinking your stomach is full, and others block the absorption of dietary fat by inhibiting lipase, an enzyme that breaks down fats.”
I keep hearing about GLP-1 analogues, like Ozempic. What should I know?
These are medications that mimic a hormone, opens in a new tab called glucagon-like peptide 1 (GLP-1) which leads to an increase in insulin production and decrease in glucagon production. For people with type 2 diabetes, where the body struggles with insulin production, these drugs help manage blood sugar levels. They can also curb your appetite and make you feel full longer by slowing down digestion.
Are weight loss drugs effective?
According to The Royal Australian College of General Practitioners, opens in a new tab (RACGP), there’s solid evidence supporting the benefits of weight loss and control measures through medication. However, it’s important to remember that these medications aren’t a silver bullet for long-term weight management.
“Without making lifestyle changes like improving your diet and increasing exercise, you might find it challenging to maintain your weight once you stop using weight loss medication,” explains Hamish.
What are the side effects of prescription weight loss drugs?
Just like any other medications, prescription weight loss drugs can come with side effects, opens in a new tab. These might include:
Upset stomach (nausea, vomiting, diarrhea, constipation)
Feeling tired
Headaches
Trouble sleeping
Faster heart rate
“The side-effects you experience will depend on the specific medication, the dosage, and how your body tolerates the drug,” Hamish explains.
"It's not just the medications themselves that cause side effects – rapid weight loss can also lead to the loss of muscle, water, and bone density as well as noticeable changes to your appearance,” Hamish says.
“This is a common misconception about 'Ozempic face, opens in a new tab.' The changes to facial structure that some people experience aren’t a direct side effect of the drug, but rather the result of rapid weight loss. If weight loss happens more gradually, these changes may be less pronounced."
Reach out to your healthcare provider immediately if you experience symptoms on any medication.
How long can you take them for?
Unfortunately, there isn’t a clear answer – it really depends on the medication, your personal health goals, and how well your body tolerates the drug. Your doctor is the best person to provide advice based on your personal circumstances.
“Weight loss drugs shouldn’t be used on their own to help you lose weight,” Hamish reminds us. “Weight is just one part of your overall health, and you should focus on eating well, staying active, and getting enough sleep , opens in a new tabfor a holistic approach to your wellbeing.”
Is weight loss medication right for me?
Losing weight can be tough. You’ve probably tried different methods, read conflicting advice, and felt frustrated at times. With so many products and treatments out there, it’s easy to feel confused about where to turn.
According to the National Health and Medical Research Council guidelines, opens in a new tab, more intensive therapies like medication, low-calorie diets, and surgery are recommended only for those at significant risk.
“Clinically, weight loss medications are typically recommended, opens in a new tab for people with a BMI over 30 or for those with a BMI between 27 and 30 who also have other health risks,” says Hamish.
Remember, weight management is about more than just losing weight. It’s about regaining your vitality, energy, and joy. The safest way to maintain a healthy weight is through a balanced diet and regular exercise. While weight loss medications can support your initial weight-loss efforts, they’re not a quick fix.
How do I access it?
You’ll need a prescription from your doctor for weight loss medications including off-label medications or approved TGA medications – essentially anything that isn’t classed as ‘complementary medicine’. Your doctor will evaluate your health, medical history and weight management goals to determine if the medication is suitable for you.
The TGA has recently made the decision to stop the pharmacies compounding, opens in a new tab their own versions of medications like Ozempic (as they had been doing to meet increased demand) from October 1 2024 due to safety concerns about unreported side effects and quality issues.
If you’ve been using these compounded weight loss drugs, it’s recommended you consult your doctor about alternative treatments and your overall health plan.
How much do they cost?
The cost of weight loss drugs can vary widely depending on the specific medication and dosage.
"Weight loss medication might be right for some people, but it's not a quick fix. It should be combined with a sustainable weight management program including a balanced diet and regular exercise. Everyone’s body will require a unique approach, so talk to your healthcare professional before embarking on a weight loss journey,” says Hamish.
Looking for advice about weight management? Find your local healthcare provider, opens in a new tab or book a telehealth appointment, opens in a new tab with your GP to discuss the best weight management approach for you.
At nib, eligible members can access support free of charge through weight management programs like MedJourney,, opens in a new tab which are designed to help people using weight-loss drugs develop sustainable weight management habits.
Please note: The information throughout this article serve as broad information and should not replace any advice you have been given by your medical practitioner.
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Dr Hamish Black
Dr Hamish Black has been a medical practitioner for more than 25 years. In addition to his role as nib group medical advisor, he still spends two days a week practising as a GP. He has spent many years working in emergency departments and in rural Australia, including a stint with the Royal Flying Doctor Service. Hamish also loves karaoke and dancing (though not that well at either, he says!), with Play that Funky Music by Wild Cherry being his karaoke favourite.