After a second injection of a product labelled retatrutide, a Victorian patient became severely unwell with acute liver injury—the seventh such hospitalization in the state since January. Liver transplant specialist Marie Sinclair, who has treated several of these patients at the Victorian Liver Transplant Unit at Austin Hospital, described the presentation: jaundice, abdominal pain, and rapid deterioration. "We have seen a recent case again, fairly similar to previous cases, where after a second dose of unregulated retatrutide there was severe liver injury," Sinclair said, as reported by ABC News on 24 August.

The immediate question for clinicians and patients in Victoria is not whether retatrutide as a molecule causes liver damage in regulated trials—it has not been approved anywhere—but whether a single contaminated batch of counterfeit vials is responsible for the cluster. TGA Chief Medical Advisor Robyn Langham told the ABC that "the localised nature" of the hospitalizations pointed to "a batch problem" rather than a nationwide supply issue. She stressed that the products being sold are counterfeit: "The retatrutide that's being sold is not the retatrutide that's currently in clinical trials." No contaminant has been publicly identified, and Langham noted her comments did not reflect a completed investigation.

What patients are actually injecting

The vials reaching Victorian emergency departments do not pass through pharmacies or prescribers. An ABC investigation published on 2 August documented sellers operating on Facebook Marketplace under pseudonyms, offering face-to-face handoffs or free delivery. Products are labelled as "research chemicals" not for human use, a disclaimer that has not prevented injection. Peptides—short chains of amino acids that signal processes such as hormone release or tissue repair—include regulated medicines like insulin and GLP-1 drugs such as Ozempic. Retatrutide is not among them.

University of Queensland researcher Timothy Piatkowski tested a set of peptides purchased from this informal market, including retatrutide, BPC-157, TB-500, and GHK-Cu. None matched the dosages printed on their labels. The TB-500 vial contained nothing. One retatrutide sample returned 190 percent of its labelled concentration—a level Piatkowski noted had produced elevated heart rate, raised liver enzymes, and gastrointestinal upset in early-stage trials. Trace lead and cadmium appeared in some vials, though below permissible daily limits. Independent assays of this kind, outlined in our guide to peptide testing, remain one of the few ways consumers can identify adulteration before injection.

Enforcement has not closed the supply gap

In April 2026, a joint operation involving the Australian Border Force and Victoria Police resulted in three arrests and the seizure of $2 million in peptide and steroid products. The TGA has separately warned social media influencers that "large fines and penalties apply to illegal advertising," including promotion of retatrutide. Queensland Health and NSW Health confirmed they had received no reports of retatrutide-linked liver toxicity as of early August. NSW Health stated it "strongly advises the community against the use of retatrutide, which is not a registered medicine in Australia."

Whether the absence of cases outside Victoria reflects lower use, different supply batches, or under-reporting in states without a centralized alert system remains unclear. The TGA does not oversee the composition, manufacturing standards, or safety of unapproved peptide products, meaning no regulatory body is positioned to issue a targeted recall if a contaminated batch is confirmed. For a broader look at what is and is not known about these compounds, see our explainer on research peptides and safety.

Sinclair's team at Austin Hospital is still awaiting laboratory results on vials recovered from the seventh patient. Langham's office has not announced a timeline for releasing analytical findings.