Weight Reducing Injections in Australia: Results, Side Effects and Safety

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(last updated May 2026)

Introduction

In recent years, weight loss injections have drawn a lot of interest online and on social media among people trying to achieve or maintain a healthy weight. People use a lot of different phrases when they search online for this topic : "weight reducing injections", "fat loss injections" , "weight reducing medications", or the "new shot for losing weight".

In Australia, these Google searches generally reflect an interest in incretin-based prescription medicines, including GLP-1 receptor agonists, now commonly used in medical weight management. These treatments can help some people reduce appetite, feel full sooner, and lose weight when used alongside appropriate medical assessment, nutrition, physical activity and follow-up care.

While successful for many, they are not medically suitable for everyone. They are prescription drugs that should only be started after a doctor has reviewed your health history, current medicines, weight-related risks, goals and follow-up needs.

In this article, we’ll cover how weight reducing injections work, what Australians can realistically expect in terms of weight loss, monthly costs, and side effects, and how they fit into a broader, holistic approach to weight management.

What Are Weight Reducing Injections?

"Weight reducing injections" are prescription medications from the incretin-based medicine group, including GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists. They are used to support weight loss by influencing appetite, metabolic processes and satiety (satiety is the feeling of fullness and satisfaction after eating, which suppresses hunger until your next meal). They are typically considered when lifestyle measures alone, such as diet and exercise, have not achieved results, and when other health issues are being caused by excess weight- such as high blood pressure, sleep apnoea, osteoarthritis or plantar fasciitis.

The injections require a doctor’s prescription, and should only be used under medical supervision as part of a structured weight-management plan.

Is "fat loss injections" an accurate term?

Not really.

The phrase fat loss injections is a common search term, but prescription injections used for weight management do not dissolve fat from one particular body area.

If someone is searching for "fat loss injections", they could be looking for one of several things:

- prescription weight management injections (such as GLP-1 agonists)

- cosmetic treatments promoted for localised fat reduction

- vitamin or supplement injections

- unapproved products sold online or through social media

Prescription weight management medicines require medical assessment. Unapproved or imported products can be unsafe. The TGA warns consumers to be cautious with weight-loss products that make unrealistic claims, are sold through overseas websites, or are promoted as a quick fix.

So, what is the "new shot for losing weight"?

When people talk about the "new shot for losing weight" , they are usually referring to newer prescription injectable medicines used in weight management- GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists.

The interest is understandable: clinical trials show that some people lose meaningful weight with these medicines, but results vary and treatment needs medical follow-up. There is no single injection that suits everyone.

A doctor needs to consider:

- whether prescription treatment is appropriate for you

- whether an injection is the right option compared with other treatments

- your medical history and current medicines

- pregnancy plans, pregnancy or breastfeeding

- weight-related health conditions

- side-effect risk

- cost, supply and follow-up needs

- whether you have adequate support for nutrition, physical activity and long-term maintenance

How Do Weight Reducing Injections Work?

Different injectable medicines work in different ways, but many affect biological pathways involved in hunger, fullness and digestion. Depending on the medicine, they may:

- reduce appetite or cravings

- help you feel full sooner

- slow how quickly food leaves the stomach

- affect blood glucose regulation

- make it easier to stay consistent with a lower energy intake

They do not remove the need for nutrition, movement, sleep and behavioural change. In clinical trials, these medicines are usually studied alongside lifestyle support. In real life, results also depend on the person's routine, dose, side effects, health conditions, stress, alcohol intake, food choices and whether treatment can be continued.

How much weight do people usually lose with weight reducing injections?

There is good trial evidence that injectable medicines can produce meaningful weight loss for some people, but the result depends on the medicine, dose, side effects, lifestyle support and whether treatment can be continued.

In major clinical trials, average weight loss ranged from about 8% to about 21% of starting body weight over 56-72 weeks, depending on the injectable medicine and dose. Trial participants also received lifestyle advice, so these results should not be read as what happens from the injection alone.

For many people, a 5-10% reduction in starting body weight is already clinically meaningful. For someone weighing 100 kg, that would be 5-10 kg. Weight loss at that level can improve blood pressure, blood glucose, fatty liver, sleep apnoea or joint pain for some patients.

Some people lose more than this, and some lose less or stop treatment because of side effects, cost, supply problems or limited response.

Your doctor can help set realistic goals for you, based on your health risks, previous attempts, side effects, dose, affordability and follow-up plan.

Who is eligible for Weight Reducing Injections?

For adults in Australia, prescription injectable medicines for weight management are generally considered in people with a BMI of 30 or above, or a BMI of 27 or above with at least one weight-related health issue, such as high blood pressure, sleep apnoea, insulin resistance, fatty liver, osteoarthritis or abnormal cholesterol.

Those thresholds do not mean treatment is automatic. A doctor still needs to decide whether the likely benefits, risks, side effects, cost and follow-up requirements make sense for the individual person.

Assessment is individual. Your doctor may consider:

- your body mass index and waist-related risk

- previous weight loss attempts

- blood pressure, blood glucose, cholesterol and liver results

- conditions such as type 2 diabetes, prediabetes, insulin resistance, fatty liver, sleep apnoea, PCOS, osteoarthritis or high blood pressure

- current medicines and allergies

- pregnancy plans, pregnancy or breastfeeding

- mental health and eating behaviour

- contraindications such as previous gallbladder, pancreatic, thyroid, kidney, liver or gastrointestinal issues

- whether the likely benefits, risks and costs make sense for you

Medical suitability is not the same as PBS eligibility. Most Australians have to pay in full for weight loss treatments- ie even if a person medically qualifies for treatment, they will still need to pay privately. There are some exceptions such as Type 2 Diabetes (and possibly other conditions in future like Fatty Liver and Cardiovascular disease). If cost is a major concern, it should be discussed before starting, as there may be ways to manage or minimise this (eg lower doses of medication, less frequent reviews over time etc).

What Is the Cost of Weight Reducing Injections in Australia?

Cost is an important consideration for most people, particularly as injectable weight-management medications in Australia are generally not subsidised under the Pharmaceutical Benefits Scheme (PBS) when prescribed specifically for weight loss. This means most people pay out-of-pocket.

Estimated Monthly Medication Cost (Australia)

Based on private prescription pricing at major Australian pharmacies (at the time of writing), injectable medications in the GLP-1 agonist class typically cost:

Approximately A$200–$250 per month at lower doses
Up to A$400–$600+ per month at higher doses

The exact monthly cost depends on:

The dose prescribed
How many injection pens are required per month
Pharmacy pricing

These figures do not include consultation or follow-up fees with a GP or specialist.

Because weight-management treatment is often longer-term, it’s important for patients to factor in ongoing costs when considering this option. Read more in our dedicated article on cost of treatment <here>.

What Are the Common Side Effects?

Like all prescription medications, weight reducing injections may cause side effects. The most common side effects are usually digestive. These may include:

- nausea

- vomiting

- reflux or indigestion

- constipation

- diarrhoea

- abdominal discomfort or bloating

- reduced appetite

- headache

- injection-site irritation

Side effects can be more noticeable when treatment starts or when doses change. A doctor may reduce risk by starting carefully, increasing gradually where appropriate, and reviewing symptoms during follow-up.

Serious side effects are uncommon/rare, but can include pancreatitis, gall bladder disease, deterioration in mental health, and potentially an increased risk of certain cancers in the longer term- your doctor will be able to talk through these areas with you, and discuss the risk/benefit of treatment.

Seek urgent medical advice if you develop severe abdominal pain, persistent vomiting, signs of dehydration, jaundice, fainting, chest pain, severe allergic symptoms, or any symptom that feels severe or rapidly worsening.

How Are Side Effects Managed?

Review appointments matter because treatment often needs adjustment.

A doctor may discuss:

- dose timing

- whether to delay a dose increase

- whether the current dose is still suitable

- hydration and meal timing

- constipation, reflux or nausea management

- blood results or other tests if needed

- whether treatment should continue, pause or stop

If you are having persistent or worrying side effects, do not wait for a routine repeat prescription. Book a review so the treatment plan can be reassessed.

Do Weight Reducing Injections work without lifestyle changes?

They work best when paired with a plan that supports long-term health.

That does not mean you need an extreme diet or unrealistic exercise routine. It means the treatment should sit alongside practical habits that protect nutrition, muscle, energy levels and long-term maintenance.

Useful support may include:

- an eating pattern that provides enough protein, fibre and micronutrients

- strength or resistance activity where appropriate

- walking or other regular movement

- sleep and alcohol review

- dietitian support if eating becomes too restricted or difficult

- psychology support if eating patterns, stress or mood are making treatment harder to maintain

- medical review if side effects, results or costs change

The medicine may reduce appetite, but your plan still needs to be sustainable in the long term.

Who should be cautious?

Weight reducing injections are not suitable for everyone.

Some people may need to avoid them, delay treatment or get specialist advice first. This can include people who are pregnant or breastfeeding, planning pregnancy, have certain endocrine cancer histories, previous pancreatitis, significant gallbladder disease, severe gastrointestinal disease, complex diabetes-related issues, severe kidney or liver disease, active eating disorder concerns, or allergy to a relevant medicine.

This is not a complete list. The safest approach is to discuss your own history with a doctor rather than assuming treatment is suitable based on someone else's experience.

Are There Alternatives to Weight Reducing Injections?

Yes. Injections are only one possible option.

Depending on the person, a doctor may discuss:

- nutrition support with an accredited practising dietitian

- structured physical activity or exercise physiology

- psychology support for eating patterns, stress, mood or behaviour change

- oral weight-loss medicines

- treatment of related conditions such as sleep apnoea, insulin resistance, PCOS or fatty liver

- bariatric surgery in selected cases

The right option depends on your health risks, preferences, previous attempts, cost, treatment suitability and access to follow-up.

The Bottom Line

Weight reducing injections can help some people achieve clinically meaningful weight loss, but they are not simple fat-melting shots and they are not suitable for everyone.

If you are searching for fat loss injections or the new shot for losing weight, the safest next step is to understand that these are prescription treatments requiring medical assessment. A doctor can help you consider whether an injection, another medication, lifestyle support, allied-health care or a different pathway is most appropriate for your health situation.

Frequently Asked Questions

Are weight reducing injections the same as fat loss injections?

Not exactly. The phrase fat loss injections is a common search term, but prescription weight management injections do not target one area of fat or melt fat at the injection site. They usually work by affecting appetite, fullness, digestion or metabolic pathways.

What is the new shot for losing weight?

People usually use this phrase to refer to newer prescription injectable medicines used in weight management. There is no single shot that suits everyone, and treatment should only be considered after a doctor assesses suitability, risks, cost and follow-up needs.

Do weight reducing injections actually work?

They can help some people lose clinically meaningful weight, especially when used with nutrition, activity and medical follow-up. Results vary by medicine, dose, health conditions, side effects, cost and whether treatment can be continued.

Who can prescribe weight reducing injections in Australia?

An Australian-registered doctor can prescribe if they assess that the treatment is clinically appropriate and safe. The prescription should be based on medical assessment, not an automatic online order.

Are weight reducing injections safe?

They can be used safely for some patients with proper assessment and monitoring, but they can cause side effects and are not suitable for everyone. Your doctor should discuss your medical history, current medicines, pregnancy plans, risks and review plan before treatment starts.

What side effects should I watch for?

Common side effects include nausea, vomiting, reflux, constipation, diarrhoea, abdominal discomfort, headache and injection-site irritation. Seek urgent medical advice for severe abdominal pain, persistent vomiting, dehydration, jaundice, fainting, chest pain or severe allergic symptoms.

How much do weight reducing injections cost?

Costs vary by medicine, dose, pharmacy, provider model, delivery fees and review needs. Many people pay privately. For a detailed breakdown, see our guide to weight loss injection costs in Australia.

Can I get an online script for weight reducing injections?

Yes, where an Australian doctor assesses that prescription treatment is appropriate and safe. If prescribed by Doctors for Weight Loss, an eScript can be sent to your phone so you can use a pharmacy of your choice.