Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Compounded weight loss injections have been having a massive moment online. But in Australia, the legal reality has shifted, and it’s far less ‘trendy’ than the social media ads suggest.
As of 1 October 2024, the Australian Government and the Therapeutic Goods Administration (TGA) introduced a total ban on the pharmacy compounding of GLP-1 replicas (like Ozempic or Mounjaro). This means that the ‘off-brand’ versions many people were accessing during shortages are no longer legal to manufacture or supply in Australia. This decision was made to prioritise patient safety, as these custom-mixed versions never underwent the same rigorous evaluation as registered medicines.
Read on as we discuss why these rules changed, what the current law says, and the risks every Australian should understand before considering unapproved options.
Compounding is a practice where a pharmacist custom-mixes a medication for an individual patient. While it’s a vital part of personalised medicine, like making a liquid version of a tablet for someone who can’t swallow, it was never meant for mass-producing replicas of popular weight loss drugs.
Interest peaked when global shortages hit, and compounded versions emerged as a ‘stop-gap’. However, because these products aren't TGA-approved, they aren't tested for safety, quality, or even if the dose in the vial matches the label.
The TGA closed the legal ‘loophole’ for these specific medications because of several growing concerns:
Compounding was intended for one-off, individual needs. However, the TGA found that some pharmacies were manufacturing commercial quantities of replicas without individual prescriptions, bypassing the safety standards required for mass-produced drugs.
Many compounded versions were found to use ‘salt’ forms (like semaglutide sodium) which have never been approved for human use. These ingredients carry unknown risks compared to the base-form used in TGA-approved Ozempic® or Wegovy®.
As of late 2024, the Australian Government moved to protect Australians from unsafe replicas by removing GLP-1 receptor agonists from the pharmacist extemporaneous compounding exemption.
It is strictly against the law to advertise prescription-only medicines to the public in Australia. The TGA has recently issued hundreds of thousands of dollars in fines to online clinics and businesses for unlawfully promoting these products.
While the TGA has removed the general exemption for GLP-1 replicas, compounding still exists for very specific, individual needs. In 2026, with supply chains for brand-name products like Wegovy® and Mounjaro® having stabilised, these ‘off-market’ versions are no longer used to bypass shortages.
Under the current Australian law and the Pharmacy Board of Australia Guidelines, a compounded injection is now reserved only for the rarest of exceptional clinical circumstances, such as:
A medically diagnosed allergy: If a patient is allergic to a specific non-active ingredient (like a preservative or filler) found in every single TGA-approved brand. This is a primary reason for extemporaneous compounding under professional supervision.
Unique delivery needs: If a patient has a physical disability that makes using a standard pre-filled pen impossible, a pharmacist may need to organise a different liquid concentration.
Exhausting all ARTG options: This only applies when every approved medication on the Australian Register of Therapeutic Goods (ARTG) has been trialled and deemed unsuitable by a specialist. The TGA advises that compounding should only be considered when no other suitable treatment exists.
True individualised care: The medication must be prepared for one specific person after a pharmacist receives a valid prescription. Mass-producing batches in anticipation of ‘orders’ is strictly illegal and violates the Therapeutic Goods Regulations 1990.
Not all injections are created equal. What you put into your body matters. Read Types of Weight Loss Injections to see the differences between compounded and approved injections and make an informed choice.
Compounded weight loss injections might seem like a convenient or cheaper alternative, but the biological reality is concerning. Research consistently shows that these unapproved versions carry significant safety risks compared to the TGA-registered medications we trust.
A landmark pharmacovigilance study (analysing data from 2018 through to late 2025) found that compounded GLP-1s were linked to much higher rates of medical errors and complications than standard formulations. Here is a deeper look at those risks:
Reports have shown a significantly higher likelihood of severe abdominal pain, nausea, and diarrhoea compared to approved products. Most notably, patients using compounded versions had a 2.35 times higher risk of hospitalisation for these side effects. Because these products aren't evaluated for quality, they may contain impurities that cause far more aggressive reactions in your gut than the standard medication.
In a laboratory setting, doses are measured with microscopic precision. In a compounding pharmacy, they are hand-mixed. Recent data reveals a 48-fold higher risk of preparation errors with compounded products. The TGA and FDA have both warned of cases where patients accidentally injected 5 to 20 times the intended dose, leading to emergency room visits for severe vomiting and dehydration.
Unlike TGA-approved Wegovy® or Mounjaro®, compounded replicas aren't tested for purity. Some unregulated sources use ‘salt’ forms (like semaglutide sodium). The TGA has explicitly warned that these salts have never been found safe for human injection and can cause unpredictable spikes in the drug's concentration in your blood.
As of December 2025, the TGA updated product warnings across the entire GLP-1 class to include the potential risk of suicidal thoughts. While the TGA notes evidence is still being monitored, it is vital that patients are observed by a specialist. With compounded versions bought online, there is often no professional safety net to monitor your mood, leaving you to manage these serious emotional shifts alone.
GLP-1 medications are temperature-sensitive. Reports throughout 2025 have flagged that compounded drugs often arrive with inadequate refrigeration. Injectable GLP-1 drugs require refrigeration; injecting a ‘warm’ peptide can be dangerous, as the protein structure breaks down, potentially causing site infections or painful red lumps at the injection point.
While the social media hype might make compounded injections look like a convenient shortcut, the biological reality is that our bodies are hardwired to protect us from sudden changes. Since the TGA-led ban in late 2024, the priority has shifted back to where it belongs: patient safety and evidence-based care. Putting your health in the hands of an unapproved replica isn't just a legal risk; it's a gamble with the very biological protections designed to keep you safe. In 2026, with supply chains for brand-name medications now stabilised, there is a much clearer, safer path towards your goals.
As you move forward, remember that the most successful health journeys are those that work with your biology, not against it. Whether you are using a TGA-approved medication or focusing on lifestyle-first strategies, the aim is to move away from the ‘diet cycle’ and build a life where healthy habits feel like second nature. By making an informed, science-backed choice today, you are giving yourself the best chance at achieving results that actually last.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.