What Are GLP-1s & How They Work for Weight Loss

If you’ve been on social media, read the news, or chatted with friends about weight loss recently, chances are you’ve heard of GLP-1s. Medications like Ozempic and Wegovy have made headlines for their role in supporting weight loss — with some calling them a “miracle drug.” But behind the hype, there’s a lot of confusion about how these medications work, who they’re for, and what happens when you stop taking them.

GLP-1 receptor agonists (or GLP-1 RAs) were originally developed for managing Type 2 diabetes, but some are now also approved for chronic weight management in patients with obesity. With rising rates of overweight and obesity in Australia — projected to affect nearly 17 million Australians by 2025 — it’s no surprise that interest in these medications has skyrocketed.

However, while GLP-1s can be effective, they aren’t a one-size-fits-all solution. And they work best when paired with lasting, healthy habits like a balanced diet, adequate protein and fibre intake, and ongoing lifestyle support.

In this blog, we’ll explore:

• What GLP-1s are and how they work
  

• Why healthy eating — especially protein and fibre — is crucial during and after GLP-1 therapy
  

• The importance of medical guidance, and why not all GLP-1-like products are safe
  

• How to build habits that support long-term success — with or without medication

Ready to get started? Let’s break it all down.

What are GLP-1 receptor agonists (GLP-1s)?

GLP-1 receptor agonists (GLP-1 RAs) are a class of medications designed to mimic the effects of a natural hormone in the body called glucagon-like peptide-1 (GLP-1). This hormone is released in response to eating and helps regulate blood sugar, slow down digestion, and make you feel full — all of which are helpful for people with Type 2 diabetes (T2DM) and those who are overweight or obese.

What GLP-1s are approved in Australia?

There are several GLP-1 medications currently approved and available in Australia. These include:

For Type 2 Diabetes (T2DM):

• Ozempic (semaglutide)
  

• Trulicity (dulaglutide)
  

• Victoza (liraglutide)

For Chronic Weight Management (in overweight or obese individuals):

• Saxenda (liraglutide)
  

• Wegovy (semaglutide)

Dual GIP/GLP-1 RA:

• Mounjaro (tirzepatide) – approved for both T2DM and weight management

Among these, Trulicity and Ozempic are available on the PBS (Pharmaceutical Benefits Scheme) under authority streamlined arrangements, meaning access may be subsidised when prescribed for eligible patients.

How do they work?

GLP-1 receptor agonists (GLP-1 RAs) mimic the action of the naturally occurring glucagon-like peptide-1 hormone, which is released by the gut after eating. This hormone plays a key role in regulating appetite, digestion, and blood sugar.

Whether produced naturally or introduced through medication, GLP-1s have several important effects:

• Delays stomach emptying – slowing down how quickly food moves through your digestive system. This means you feel fuller for longer after eating, which helps with portion control.
  

• Reduces appetite – by acting on the brain’s appetite centres, helping reduce food cravings and how much you eat.
  

• Stimulates insulin secretion – when blood sugar levels rise after eating, GLP-1s help the pancreas release insulin (a hormone that lowers blood sugar).
  

• Suppresses glucagon secretion – glucagon is a hormone that raises blood sugar; by reducing its release, GLP-1s help prevent excessive glucose production by the liver.

Why this helps people with Type 2 Diabetes — and why weight loss matters

For people with Type 2 diabetes (T2DM), these effects help improve blood sugar control, particularly after meals. But there's another important benefit: weight loss.

People with T2DM often struggle with insulin resistance, where the body doesn’t respond properly to insulin. Carrying excess weight, especially around the abdomen, can worsen this condition. By helping people lose weight, GLP-1 RAs reduce insulin resistance, improve metabolic function, and can even lower the amount of medication needed over time.

In fact, some GLP-1s — such as Ozempic,Trulicity, and Mounjaro — were originally developed and approved to treat diabetes but were later found to have clinically significant weight loss benefits. That’s why other versions, like Wegovy and Saxenda, were specifically approved for people with obesity or overweight, even if they don’t have diabetes.

GLP-1s: Why the hype, and what you need to know

In the past year, GLP-1s — especially Ozempic — have become household names, thanks to viral social media posts and headlines about celebrities using them for rapid weight loss. But what many people don’t realise is that Ozempic is only approved in Australia for the treatment of Type 2 diabetes, not for weight loss.

So how are people still able to access it?

The rise of off-label and compounded use

Due to high demand and media-driven hype, some people have sought out compounded versions of semaglutide (the active ingredient in Ozempic and Wegovy) from online pharmacies or clinics — especially during recent medication shortages. But this comes with serious risks.

What are compounded medicines?

Compounded medicines are specially prepared by pharmacists to meet the needs of an individual patient — for example, if someone is allergic to an ingredient in a commercially available medication. While this can be medically appropriate in certain cases, it’s not the same as using a TGA-approved product.

According to the Therapeutic Goods Administration (TGA):

“Compounded medicines can have a different strength and may use different ingredients compared to the original medicine. This can affect patients in different ways and may cause unknown short-term and long-term side effects.”

In essence, these compounded versions:

• Have not been evaluated by the TGA for safety, quality, or effectiveness
  

• May contain inaccurate dosages or harmful ingredients
  

• Are sometimes distributed by unregulated or even criminal online operations
  

• Can pose risks such as unexpected side effects or interactions with other medications

What happens when you stop taking GLP-1s?

GLP-1 medications can be incredibly effective for supporting weight loss and blood sugar control — but they’re not meant to be used forever. For many people, especially those using them for weight management rather than diabetes, there may come a time when the medication is stopped. Whether it's due to cost, availability, side effects, or reaching a goal weight, the question then becomes:

What happens next?

Appetite may return

Once you stop taking a GLP-1 medication, its effects on hunger and fullness gradually wear off. The slowed digestion, appetite suppression, and increased satiety you may have experienced while on the medication can diminish. As a result, it might feel harder to stick to smaller portions or avoid snacking, especially if those habits weren’t reinforced during treatment.

Weight regain is common

Studies and clinical experience show that weight regain is common after stopping GLP-1s, particularly if long-term changes in eating and activity patterns haven't been established. In some cases, individuals regain most or even all of the weight they lost.

That’s because while GLP-1s support weight loss by affecting hormones and hunger, they don’t necessarily change behaviour or mindset — two key components for lasting success.

This is where lifestyle makes the biggest impact

The most successful outcomes come when GLP-1s are used in combination with a long-term healthy lifestyle. That includes:

• Prioritising protein-rich meals that help preserve muscle mass and keep you full
  

• Including plenty of fibre to support gut health and appetite control
  

• Creating sustainable habits like meal planning, regular movement, and mindful eating

In other words, think of the medication as a jumpstart — but the lasting change comes from what you do every day.

Why protein matters

If you’re coming off GLP-1 therapy — or planning for how to support your results long term — protein is one of the most important nutrients to focus on.

Here’s why.

Protein preserves muscle, not just “weight”

When people lose weight, it’s not just fat they lose — muscle can be lost too, especially if protein intake is too low. That’s a problem, because muscle mass supports metabolism. The more muscle you have, the more energy your body burns at rest.

GLP-1s may lead to reduced food intake overall, which can put people at risk of inadvertently undereating protein. That makes it even more important to prioritise protein during meals and snacks, especially as you transition off the medication.

Protein helps you stay fuller for longer

Like GLP-1s, protein helps increase satiety (fullness) and reduce hunger. Including a good source of protein in every meal can help stabilise your appetite naturally, even when the appetite-suppressing effects of GLP-1s are no longer present.

How much protein should you aim for?

The ideal amount of protein varies depending on your age, weight, and activity level. But as a general guideline, most adults benefit from:

• 1.2–2.0 grams of protein per kilogram of body weight per day, especially during weight loss or maintenance
  

• Spacing protein intake evenly throughout the day to support muscle retention and satiety

Read related article: Are There Risks That Come with High-Protein Diets?

Making protein easy and sustainable

Whole food sources like meat, eggs, fish, legumes, and dairy are excellent options. But many people find it helpful to include portable, real-food snacks that are high in protein — especially during busy days.

For example, brands like Chief offer bars and snacks (with 14g-18g of protein) made with real ingredients and no artificial additives, making it easier to get quality protein on the go — whether you’re commuting, travelling, or just need a post-lunch boost.

How fibre plays an important part

When it comes to long-term weight maintenance after GLP-1 therapy, fibre is often the unsung hero. While protein helps with muscle preservation and satiety, fibre plays an equally important role in helping you stay full, keep your digestive system happy, and support overall metabolic health.

Fibre keeps you feeling full

Like GLP-1s and protein, fibre slows down digestion, helping you feel satisfied for longer after eating. It adds bulk to your meals without adding calories — which helps reduce hunger and snacking between meals.

There are two types of dietary fibre:

• Soluble fibre, which forms a gel-like substance in the gut and slows stomach emptying (a similar effect to GLP-1s)
  

• Insoluble fibre, which adds bulk to stools and helps keep things moving

Both types contribute to feelings of fullness and play a key role in natural appetite regulation.

Fibre supports gut health and appetite signals

Your gut and brain are constantly communicating through what's known as the gut-brain axis. A high-fibre diet helps maintain a healthy gut microbiome, which can support better regulation of hunger hormones like ghrelin and leptin — making it easier to tune into natural hunger cues.

Fibre supports blood sugar stability

Because fibre slows the absorption of glucose, it can also help keep your blood sugar levels more stable, reducing spikes and crashes that lead to cravings. This is especially important for people managing insulin resistance or Type 2 diabetes — even after coming off GLP-1s.

How to add more fibre to your diet

Most Australians don’t get enough fibre. Aim for at least:

• 25 grams per day for women
  

• 30 grams per day for men

Great sources include:

• Vegetables (especially leafy greens, broccoli, carrots, and squash)
  

• Fruits (with skin on)
  

• Legumes (like chickpeas, lentils, and beans)
  

• Whole grains (like oats, quinoa, and brown rice)
  

• Nuts and seeds

Some snacks — like Chief’s collagen bars, made with ingredients such as nuts, MCT oil, acacia fibre (a natural prebiotic), and whole food sweeteners like monk fruit and organic maple syrup — offer a convenient way to boost both protein and fibre intake while supporting appetite regulation between meals.

Conclusion: It’s not just about the medication – it’s also about the mindset

GLP-1 medications can be a powerful tool for weight loss — but they’re not a magic fix. In fact, one of the most important things to understand is that lasting change comes from the habits you build, not just the medication you take.

GLP-1s can help you start — but habits keep you going

While GLP-1s may make it easier to eat less, they don’t teach you how to eat well. That’s where mindset, education, and routine come in. Learning to build balanced meals, listen to your hunger cues, and make healthier choices consistently is what sets the foundation for long-term success.

When people come off GLP-1s without changing their eating habits, weight regain is very common. But when the medication is paired with sustainable lifestyle changes — like planning meals, prioritising protein and fibre, and moving regularly — the results are far more likely to last.

Shift from “dieting” to “daily living”

Rather than thinking of GLP-1s as a diet or short-term phase, it helps to view your journey as a transition to healthier daily living. That includes:

• Choosing whole foods more often
  

• Reducing ultra-processed snacks and takeaways
  

• Including regular movement in a way that suits your lifestyle
  

• Practising self-compassion and flexibility

Sustainable change isn’t about perfection — it’s about progress, consistency, and mindset.

Support tools can help

You don’t have to rely on willpower alone. Tools like:

• Meal prep strategies
  

• Portable, real-food snacks (like those made by Chief)
  

• Tracking progress or journaling
  

• Speaking with a dietitian, healthcare professional, or health coach

…can all help you stay on track and feel confident navigating life after medication.