Mounjaro: A Comprehensive Guide for Australian Patients


Mounjaro can result in a 20-25% body weight loss. The injectable medication Mounjaro (Tirzepatide) was recently published in the New England Journal of Medicine as being an effective medication available for the treatment of obesity. Mounjaro in Australia is TGA approved for the management of diabetes and requires a prescription following a consultation with a healthcare professional.  In this comprehensive guide, we will delve into the availability of Mounjaro in Australia and provide guidance on navigating the process of obtaining expert advice. This is general information only. Your doctor will decide on a personalised treatment plan for you that may or may not include medications.

Understanding Mounjaro 

Mounjaro (active ingredient Tirzepatide) is used to manage blood sugar in people with diabetes and has shown strong evidence in global studies for a reduction in body weight by over 20%. A major global study published in the New England Journal of Medicine, treating patients with obesity alone (without diabetes) showed over a 20% weight loss, with the majority of weight reduction occuring in the first 12 months.

Mounjaro change in body weight percentage

Mounjaro functions by suppressing appetite and promoting a quicker sensation of fullness, thereby facilitating calorie reduction. In simple terms, it makes you feel fuller by slowing down the emptying of your stomach. 

When Will Mounjaro be Available in Australia? 

Mounjaro is now accessible in Australia as a prescription medication. To obtain Mounjaro, a prescription from a licensed healthcare professional is required.

Is Mounjaro Approved by the TGA?

Mounjaro (tirzepatide) is currently TGA approved for the treatment of type 2 diabetes in adults, it has not received TGA approval for the specific treatment of obesity.

Mounjaro has been approved by both the UK Medicines and Healthcare Products Regulatory Agency (MHRA) and the US Food and Drug Administration (FDA) for weight loss and weight management in individuals 18 years and over with a BMI of 30 or more or a BMI of 27 or more and at least one weight related health problem such as pre-diabetes, high blood pressure or high cholesterol.

Is Mounjaro the same as Saxenda or Ozempic? 

While all these medications can assist in diabetes and weight management, they employ different mechanisms of action. 

Saxenda, containing liraglutide, functions as a GLP-1 receptor agonist and requires daily injections. Ozempic (semaglutide) is also a GLP-1 hormone and works in a similar way with weekly injections. 

Mounjaro, on the other hand, contains tirzepatide and acts as a dual-acting glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist. It is indicated for diabetes management and is administered as a once-a-week injection. The GLP-1 receptor plays a pivotal role in regulating appetite and calorie intake, with receptors present in various brain regions responsible for appetite regulation. 

In simple terms, Mounjaro works on two receptors instead of one, as is the case with Ozempic (semaglutide). This is called a synergistic effect. This seems to be the reason for the increased effectiveness of the medication for blood sugar control and weight loss.

How does Mounjaro Compare to Ozempic for Weight Loss? 

The latest clinical trials have shown that Mounjaro was more effective than Ozempic, with patients achieving up to 22% weight loss. The top line is that Mounjaro (tirzepatide) is a more effective drug all round, producing more weight loss and a greater reduction in hemoglobin A1C (the key measure of blood sugar control in diabetes).

How Much Weight Loss Occurs with Mounjaro?

The SURMOUNT trial demonstrated the effectiveness of Mounjaro. This phase 3 controlled study involved 2,539 participants who were randomly assigned to receive either tirzepatide (at 5, 10, or 15 mg) or a placebo. After 72 weeks of treatment, the following outcomes were observed:- Those who received the placebo experienced an average weight loss of 3.1 percent.
– Participants taking 5 mg of tirzepatide achieved an average weight loss of 15 percent.
– The 10 mg tirzepatide group saw an increased weight loss of 19 percent.
– In the 15 mg tirzepatide group, the average weight loss reached 20.9 percent. The majority of weight reduction occured in the first 12 months.

It will also help with insulin sensitivity and blood sugar control reducing the complications of diabetes.  

The starting dose is 2.5mg once a week. The doctor will adjust the dose every four weeks to a maximum of 15mg weekly. 

What if I am taking other medications? 

Certain medications have the potential to disrupt the effectiveness of Mounjaro. 

When Mounjaro is combined with drugs containing sulfonylurea or insulin, it can lead to hypoglycemia (low blood sugar). This may necessitate a reduction in the dosage of your sulfonylurea or insulin. 

Mounjaro may also influence the function of some medications. 

Mounjaro has the ability to delay gastric emptying. If you are taking oral medications, such as those with slow-release formulations, drugs that are rapidly absorbed from the stomach, medications with a narrow therapeutic index (like warfarin or digoxin), or an oral contraceptive, Mounjaro might impact their efficacy. Your prescriber and pharmacist will help if you need any clarification surrounding the medications you take. 

How is Mounjaro injected? 

Currently in Australia, Mounjaro is only available in a single-use vials. It is administered via subcutaneous injection once a week. How to inject Mounjaro will be explained to you by your healthcare professional. After being trained by your healthcare professional, you can inject Mounjaro yourself at home or if you prefer, your pharmacist can also help.  

Read important Consumer Medicine Information about Mounjaro here. 

How is Mounjaro stored? 

Your pharmacy will store Mounjaro in the fridge between 2 and 8 degrees celcius. However, it is ok to store Mounjaro out of the fridge below 30 degrees celcius for up to 21 days. It may even ease administration to inject it when at room temperature. So, rest assured if you are planning on having your medication delivered after having it prescribed by your doctor, this is perfectly ok and will not require any special refrigeration while in transit.  

Contraindications of Mounjaro: When is Mounjaro not suitable? 

Certain conditions and medical histories may preclude the use of Mounjaro. It is crucial to be aware of these contraindications: 

  • Personal or family history of thyroid cancer or multiple endocrine neoplasia. 
  • Hypersensitivity to tirzepatide. 
  • Pregnancy or individuals under 18 years of age. 
  • Pre-existing conditions, including pancreatitis, kidney disease, gallbladder disease, diabetic retinopathy. 
  • BMI below 27.

Side effects and risks of Mounjaro 

Mounjaro may be associated with some common side effects, including nausea, diarrhea, vomiting, constipation, or reflux. In studies, most nausea, vomiting and diarrhea events occurred while the dose of Mounjaro was being increased. These events decreased over time. Your doctor will help with advice to minimise these symptoms.   

Serious side effects are rare but may include pancreatitis (inflammation of the pancreas), kidney or gallbladder problems or an allergic reaction to Mounjaro. In these cases, the prescriber should be notified immediately.  

Mounjaro weight loss

Can you switch from Ozempic to Mounjaro?

Yes, this is a potential option if it is deemed appropriate and safe by your prescribing clinician. The transition process would typically begin with shifting from your current Ozempic dose to 2.5mg of Mounjaro, starting seven days after your last Ozempic dose. After a four-week period on 2.5mg, the possibility of increasing the dose to 5mg can be explored. Your clinician will thoroughly assess your current progress, overall health, and engage in a discussion regarding potential side effects or risks. This collaborative decision will be made after careful consideration of your individual circumstances.

Can you switch from Saxenda to Mounjaro (or Ozempic)?

Yes this is possible under the guidance of your clinician. It’s important to explore the reasons and rationale behind the switch and discuss the risks versus the benefits. If you have diabetes, there is the possibility of a transient increase in your blood sugar levels and HbA1c, this is unlikely to be clinically significant in the long term.

As discussed above, Saxenda is a once daily GLP-1 injection compared to Ozempic and Mounjaro that are once weekly injections.

The dose change will have to be discussed carefully with your clinician, but it is likely that you will need to move to an equivalent or starting dose of the once weekly medication. It is crucial to carefully time the transition between treatments. Patients who are effectively tolerating a once-daily GLP-1 receptor agonist therapy at the maximum therapeutic dose should commence a once-weekly GLP-1 receptor agonist on the day following their last once-daily dose.

For those individuals who either cannot tolerate the maximum dose or are switching to a once-weekly GLP-1 receptor agonist due to gastrointestinal (GI) adverse effects, the recommended approach is to discontinue the once-daily medication. You should wait until your symptoms have completely resolved before initiating the lowest available dose of the chosen once-weekly GLP-1 receptor agonist.

Sign Up for a Clinician Led Weight Management Program 

Embarking on the journey to receive medical assistance for weight management commences with a discussion with a healthcare professional. This could be a general practitioner (GP) or a specialised weight management clinic such as Medmate. During the consultation, the healthcare professional will meticulously assess your medical history, current health status, and previous weight loss attempts and goals. Your doctor will decide on a personalised treatment plan for you that may or may not include medications.

Weight management assessment 

Medmate doctors adopt a comprehensive approach to weight management, taking into account factors such as your Body Mass Index (BMI), underlying health conditions, and the efficacy of past weight loss endeavors. Eligibility for the medically assisted program is determined when your BMI exceeds 30, and the process initiates with an initial comprehensive consultation followed by the issuance of a request for initial blood tests. 

Calculate your BMI here.

Weight management program 

Following the initial assessment, you will be scheduled for a comprehensive weight management program with a Medmate doctor. This program encompasses: 

– Establishing your target weight and body mass index. 

– Evaluating your current caloric intake. 

– Determining the target caloric intake aligned with your weight management objectives. 

– Setting weekly exercise goals, beginning with a daily 20-minute walk. 

– Reviewing blood test results. 

– Issuing prescriptions for medications if deemed clinically appropriate. 

– Providing instructions for at-home care. 

– Outlining a program for regular review with the Medmate nursing and medical team. 

Lifestyle Considerations 

While medications can significantly assist in weight management, it is vital to remember that it is not a standalone solution. Achieving and maintaining a healthy weight necessitates the incorporation of healthy lifestyle choices. At Medmate, we are passionate about helping you to achieve permanent weight loss to improve your immediate health and quality of life and maximise your healthspan. 

Your Medmate prescriber will help you to consider the following lifestyle factors to complement your medication: 


A high protein and nutritious diet is paramount to successful weight management. Your doctor will guide you through calorie tracking and set your daily calorie target. You must achieve a sustainable daily calorie deficit (at least by 500 calories). Medications may assist in acheiving this goal. Referral to a dietitian may also be recommended to formulate a meal plan aligned with your goals. It’s important to retain lean muscle mass and will involve tracking your macro nutrients to ensure you hit your protein targets for each day. We recommend a tracker such as My Fitness Pal to track daily calories and macros.

Calculate your basal metabolic rate and subtract 500 to get your daily target. For example if your basal metabolic rate was 2000 calories, subtract 500 to get a daily target of 1500 calories.

Calculate your basal metabolic rate here.

Physical activity 

Gradually integrating regular exercise into your routine can contribute to the attainment and maintenance of a calorie deficit and a healthy weight. The objective is to increase daily movement while adhering to your calorie target, eventually creating a calorie deficit conducive to weight reduction. Increasing lean muscle mass over time means your body burns more energy at rest allowing you to maintain a healthy weight and a leaner and more muscular physique. It’s a learning curve, the first step is to kick start the calorie deficit, measure results regularly and learn about how to incorporate both aerobic and resistance activity into your daily life. This is about lifestyle change. In time, your new habits will involve a healthier diet and regular activity that will keep you lean for the long term.

Stress management 

Stress can disrupt eating habits and contribute to weight gain. Exploring stress-reduction techniques such as mindfulness, meditation, or yoga can be valuable in maintaining a healthy lifestyle. 


In summary, Mounjaro is accessible in Australia via prescription for qualifying patients. Your initial step should involve consulting with a healthcare professional to develop a personalised management plan. It is essential to recognize that medications are most effective when incorporated into a comprehensive approach for diabetes and weight management, encompassing diet, exercise, and professional guidance. 

Achieving and sustaining a healthy weight is a journey, and with the right support and direction, you can make substantial progress toward your objectives. Always prioritize your health and safety by seeking guidance from a healthcare professional before initiating any weight management medication. 

Please bear in mind that the information provided in this guide is for informative purposes exclusively and should not replace the counsel of a qualified healthcare professional. Always seek professional guidance tailored to your specific health requirements and goals.

Booking a Free Weight Loss Consultation 

Medmate’s Clinican Led Weight Management service starts by completing a short registration form. One of our friendly nurses will give you a free call for a quick chat to explain how everything works. Register for a weight loss consultation with this expression of interest form and we will be in touch shortly.

About the Author

  • Dr Ganesh Naidoo

    BSc(biomed), MBBS, FRACGP is an Australian General Practitioner. He has significant clinical experience in multiple regions of Australia and has a passion for health transformation to improve clinical outcomes for all patients.

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