Counterfeit peptide linked to serious oesophagus injury
14 Sep 2026
The patient experienced severe, uncontrolled vomiting after using the unapproved product and later suffered a torn oesophagus.
Testing found that the product did not contain retatrutide as advertised. Instead, it contained undeclared semaglutide at a level eight times higher than that found in products listed on the Australian Register of Therapeutic Goods (ARTG).
Dr Terri-Lynne South, Chair of RACGP Specific Interests Obesity, said the case raised concerns about people not knowing what they are actually taking.
She said the excessive dose found in the product was particularly concerning from a safety perspective.
On Monday, the Therapeutic Goods Administration (TGA) issued another urgent warning about unapproved peptide products. Retatrutide is currently being studied in clinical trials and has not been approved for use.
The TGA said products claiming to contain retatrutide that are obtained outside clinical trials may be counterfeit and should not be used.
Consumers have been warned against using unapproved peptide products, particularly those bought online, obtained from overseas or supplied in unmarked vials.
TGA Chief Medical Advisor Professor Robyn Langham said the main risks include not knowing what substance a product contains, how much is present, whether it is sterile or whether it contains contaminants or toxins.
These risks are especially concerning for injectable products, where poor or non-sterile manufacturing can increase the risk of infection and serious immune reactions, including anaphylaxis.
People who inject these products also face risks from incorrect dosing, unsafe injection methods and serious adverse reactions.
The TGA said illegal peptide use continues to grow in Australia, with social media influencers promoting the products for weight loss and muscle growth.
Dr South said GPs have an important role in asking patients about medicines and supplements they may be taking without a prescription.
She recommended starting with open questions about over-the-counter and complementary products, helping patients feel comfortable discussing their use without fear of judgement.
The TGA said it is investigating the source of the products and working to remove them from the market.
TGA head Professor Anthony Lawler said the latest safety alert showed why consumers should only use products approved for supply in Australia.
He said imported products that have not been approved by the TGA are not assessed for safety in the same way as medicines approved for supply in Australia.
In June, the TGA added unapproved peptide products to its priority areas for regulatory action as part of increased monitoring and enforcement.
Counterfeit peptide linked to serious oesophagus injury
Source: Therapeutic Goods Administration (TGA); RACGP newsGP