Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Compounded weight loss injections have been making waves online, often marketed as “customised” alternatives to standard medications like semaglutide or liraglutide. But if you’re in Australia, it’s important to know the legal and safety landscape before considering them. These injections are prepared in pharmacies for specific patients under doctor supervision, yet they fall into a complex regulatory grey area. While they might sound convenient or cheaper, compounded injections are not always TGA-approved for weight loss, meaning there are legal and safety implications. In this article, we explore what compounded weight loss injections are, when they might be prescribed, why they can be considered illegal, the role of the TGA, and the risks involved.
What Are Compounded Weight Loss Injections
Compounded weight loss injections are medications prepared by a pharmacist for an individual patient based on a prescription. Unlike standard, commercially manufactured injections, these are “custom-mixed” to suit specific dosing or formulation needs. Compounding allows for flexibility, but it also introduces legal and safety considerations, especially when used for weight loss outside approved indications.
Types of Compounded Weight Loss Injections
Several types of compounded injections are circulating, often mimicking or combining standard GLP-1 medications:
A version of the widely prescribed GLP-1 used for appetite control, prepared in smaller or modified doses.
Another GLP-1 peptide, sometimes compounded for patients who cannot tolerate the standard formulation.
A newer GLP-1/GIP dual-acting peptide, occasionally compounded for specialised dosing needs.
Pharmacies may combine different peptides to theoretically enhance weight loss effects, though evidence is limited.
Other peptides that influence hunger and satiety are sometimes compounded, often without TGA-approved weight loss indications.
When Compounded Weight Loss Injections Are Prescribed
Compounded injections are only legally and ethically prescribed in very specific situations:
Approved medications are unavailable – for patients who cannot access standard formulations due to shortages.
Patient cannot tolerate standard formulations – when side effects prevent the use of commercial injections.
Dose adjustment is medically necessary – if a customised dose is required for safety or efficacy.
Prescribed by a licensed doctor – a valid prescription is essential.
Prepared by a registered compounding pharmacy – compounding must comply with Australian pharmacy regulations.
Why Are Compounded Weight Loss Injections Considered Illegal
Compounded injections can be considered illegal under certain conditions:
No TGA approval for weight loss indication – the Therapeutic Goods Administration only approves some medications for diabetes or obesity under specific circumstances.
Mass production outside compounding rules – producing large batches without individual prescriptions is illegal.
Sale without a valid prescription – selling injections online or in clinics without prescriptions breaches Australian law.
Use of unapproved active ingredients – ingredients not approved by the TGA pose legal and health risks.
Importation from unregulated overseas sources – this is illegal and increases risk of contamination or counterfeit products.
How the TGA Regulates Compounded Medications
The TGA monitors compounding practices to ensure patient safety. Registered pharmacies must follow strict standards for:
Accurate dosing and labelling
Sterility and contamination control
Use of approved ingredients only
Prescription verification by a licensed doctor
Medications prepared outside these guidelines fall outside TGA oversight, increasing legal and health risks.
Risks of Compounded Weight Loss Injections
Even when prescribed by a doctor, compounded injections carry additional risks compared with standard, approved medications:
Incorrect dosing or potency – small errors can affect effectiveness or safety.
Contamination or sterility issues – infections or reactions are possible.
Unknown ingredient quality – active ingredients may vary in strength.
Increased side effects – gastrointestinal symptoms, dizziness, or fatigue may occur.
Limited safety and efficacy data – there is little research on compounded injections for weight loss in teens or adults.
Conclusion
While compounded weight loss injections exist and can be legally prescribed in very limited situations, they are not a simple or risk-free alternative to standard medications. Using unapproved or mass-produced compounded injections is illegal in Australia and can pose serious health risks. The safest approach is to work with a licensed healthcare provider and use TGA-approved medications for weight management whenever possible. Compounded injections should only ever be considered when medically necessary and under strict professional supervision.
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.