Exploring Weight Loss Drugs in Australia: Wegovy, Mounjaro, and the Promise of GLP-1 Agonists

Unless you've been living under a rock, you're likely to have heard about the new weight loss wonder drugs that are taking the world by storm. Long have we yearned for a simple drug that helps us lose weight with minimal effort. Well, they've arrived... sort of. These new drugs known as Wegovy (Ozempic) and Mounjaro, are producing astonishing weight loss results, with some comparable to that of weight loss surgery. So do these new wonder-drugs live up to the hype? Can we really lose weight effortlessly, without any concern of adverse effects?

These drugs belong to a class called GLP-1 receptor agonists, and Mounjaro, in particular, is a dual-agonist that enhances its effectiveness. For Australians looking for a medical solution to weight loss, these medications represent a promising option—though not without considerations.

This guide explores Wegovy and Mounjaro, how they work, their effectiveness, benefits, and risks. We’ll also briefly discuss Ozempic, which shares the same active ingredient as Wegovy but serves a different purpose.

Wegovy: A Weight Loss Breakthrough

Wegovy (semaglutide) is a once-weekly injectable medication specifically designed to aid in weight loss. It works by mimicking the GLP-1 hormone, which regulates appetite, slows digestion, and enhances feelings of fullness. It is approved for Australians with a Body Mass Index (BMI) of 30 or higher, or 27 or higher with weight-related health issues, and is intended to complement a reduced-calorie diet and increased physical activity.

How Effective Is Wegovy?

• Clinical trials have shown that Wegovy users can lose an average of 15% of their body weight over a period of 68 weeks when combined with lifestyle changes.
• Some individuals achieved weight loss of up to 20%, a milestone for non-surgical weight management.

Mounjaro: The New Heavyweight

Mounjaro (tirzepatide) is a newer medication that targets both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors. This dual-action mechanism enhances insulin secretion, reduces appetite, and slows gastric emptying. While currently approved in Australia for managing blood sugar in adults with type 2 diabetes, its weight loss effects have made it a major focus of attention.

How Effective Is Mounjaro?

• Clinical trials reveal Mounjaro can help users lose up to 22.5% of their body weight, making it one of the most effective weight loss medications available. For comparison, the sleeve gastrectomy (weight loss surgical option) averages a decrease of between 25-35% of body weight. So Mounjaro is nipping at the heels of surgical intervention, and is much less invasive.
• In a direct comparison, participants on the highest dose of Mounjaro lost an average of 23.6 kg, compared to 15 kilograms for those on semaglutide (Wegovy).

Ozempic: How It Differs from Wegovy

Ozempic contains the same active ingredient as Wegovy—semaglutide—but is prescribed at a lower dose (2.0 mg Vs 2.4 mg max dosage) and is primarily used for managing type 2 diabetes. Weight loss with Ozempic is often a secondary benefit, whereas Wegovy is specifically formulated for weight management.

How These Medications Work

Both Wegovy and Mounjaro work by influencing the body’s appetite-regulating and digestive hormones:

1. Suppressing Appetite: By mimicking GLP-1 (and GIP for Mounjaro), these drugs reduce hunger and cravings.
2. Enhancing Satiety: They increase feelings of fullness, making it easier to stick to reduced-calorie diets.
3. Slowing Digestion: Delayed gastric emptying reduces the overall amount of food consumed.
4. Regulating Blood Sugar: Particularly beneficial for individuals with type 2 diabetes, these medications improve insulin sensitivity and lower blood glucose levels.

Benefits of Wegovy and Mounjaro

1. Significant Weight Loss

• Wegovy helps users lose an average of 15% of their body weight, while Mounjaro users can achieve up to 22.5%.

2. Improved Metabolic Health

• Both medications enhance insulin sensitivity, lower blood sugar levels, and reduce HbA1c, making them especially valuable for those with prediabetes or type 2 diabetes.

3. Reduced Risk of Comorbidities

• Effective weight loss can alleviate conditions such as high blood pressure, sleep apnoea, and fatty liver disease.

4. Convenient Dosing

• These drugs are administered via once-weekly injections, which is easier to manage than daily tablets or injections.

5. Enhanced Quality of Life

• Many users report increased energy, improved mobility, and higher self-esteem.

Risks and Considerations

1. Gastrointestinal Side Effects

• Common issues include nausea, vomiting, diarrhoea, and constipation, especially during the initial weeks of treatment.

2. Potential for Weight Regain

• Discontinuing these medications often leads to weight regain, highlighting the importance of continued lifestyle changes. This is particularly prevalent when diet and lifestyle interventions have been left on the shelf, and responsibility is handed over completely to medication.

3. High Costs

• In Australia, Wegovy and Mounjaro are not yet subsidised under the Pharmaceutical Benefits Scheme (PBS), and their cost can exceed $600 per month.

4. Unknown Long-Term Safety

• These medications are relatively new, and their long-term safety, particularly regarding the pancreas and thyroid, remains under investigation.

5. Contraindications

• Not suitable for individuals with a history of thyroid cancer or pancreatitis, among other conditions.

Weight Loss Statistics at a Glance

Who Are These Medications Suitable For?

• Ideal Candidates: Australians with a BMI ≥30, or ≥27 with weight-related conditions, who have not achieved significant results through diet and exercise alone.
• Caution Needed: People with certain medical histories, such as medullary thyroid carcinoma, should avoid these medications.

Wegovy and Mounjaro are transforming the landscape of weight management in Australia, offering life-changing results for individuals who have struggled with traditional weight loss methods. I am a huge advocate for using all the tools we have available to us when it comes to helping reduce the burden of disease. However, these drugs are not a silver bullet. These medications work best when combined with lifestyle changes, including a healthy diet and regular exercise. I need to stress this here:

"You will lose weight on these drugs because you are eating less calories, but you are also eating less protein, vitamins & minerals." 

I have observed firsthand physical sighs of malnourishment, thinning hair, brittle nails, slow wound healing. Yes these people lost weight but at what cost? This does not have to be the case. Don't blindly trust these medications to do all the heavy lifting when it comes to weight loss. Share the workload by maintaining a healthy diet and regularly exercising to prevent malnourishment. These drugs present a wonderful opportunity, and although the high costs and lack of PBS subsidies remain significant barriers, the potential benefits may outweigh these challenges for many.