Australia's medicines regulator, the Therapeutic Goods Administration (TGA), has issued a warning about the serious risks of unapproved peptide products after a patient was hospitalised with a torn oesophagus following use of a counterfeit version of the experimental weight-loss drug retatrutide.
The patient experienced severe and uncontrollable vomiting after taking what they believed was retatrutide, leading to the oesophageal tear, which can be life-threatening. The TGA obtained a sample of the product and found it contained a different peptide that also targets hunger, called semaglutide, and no retatrutide.
Unapproved drug widely promoted on social media
Retatrutide is a type of drug known as a peptide, which are strings of amino acids that act as chemical messengers in the body, involved in functions such as hormone activity, digestion, immune defence, and tissue growth. The peptides in retatrutide mimic hunger hormones.
Despite not being approved by the TGA or overseas regulators, and being unable to be legally prescribed or sold in Australia, the drug has been widely promoted on social media and sold on the black market under names including retatrutide, Reta, R-10 and R-20, often in unmarked vials.
Sample contained eight times the approved semaglutide level
The TGA's analysis revealed that the amount of semaglutide detected in the counterfeit product was approximately eight times higher than levels found in approved semaglutide products assessed by the TGA.
Prof Robyn Langham, the TGA's chief medical adviser, said products sold online may be fake or counterfeit and could contain ingredients posing serious health risks.
“The biggest risks with unapproved peptide products are not knowing what is in the vial, how much of or even what substance it contains, whether it is sterile, or whether it contains other contaminants or toxins,” she said. “These risks are particularly concerning for injectable products, where contaminated or non-sterile manufacturing can increase the risk of infection and harmful immune responses including anaphylaxis.”
Additional risks and prior warnings
Langham noted that people who self-inject face additional risks such as incorrect dosing, unsafe injection technique, and serious adverse reactions.
The Victorian health department issued a similar warning in June after being notified of six cases of acute liver toxicity associated with products labelled as retatrutide. Prof Anthony Lawler, head of the TGA, said imported and illegal products are “not subject to the same controls over the quality or efficacy of the goods when compared with medicines approved for supply in Australia”.
Australia's chief medical officer has previously issued a public health warning about unapproved and non-prescribed peptides, following reports of serious adverse effects including liver damage, inflammation, and severe allergic reactions.
