Overview: A new imaging wrinkle around popular GLP-1 medications
GLP-1 receptor agonists, a class of drugs that has surged in popularity for weight loss and type 2 diabetes management, are facing fresh scrutiny. While these medications—sold under names like Ozempic, Wegovy, and Mounjaro—continue to help many shed pounds, doctors are now noting unfamiliar patterns on PET-CT scans. These patterns could mislead clinicians about a patient’s cancer risk or inflammatory status, potentially delaying diagnoses or prompting unnecessary procedures.
What PET-CT scans measure and why GLP-1s matter
Positron emission tomography combined with computed tomography (PET-CT) is a powerful tool for spotting cancer and inflammatory diseases. The test uses a radioactive tracer (FDG) that cells with high metabolic activity absorb at a higher rate. Cancer cells, inflamed tissues, and other abnormal areas typically light up on the scan. The CT portion adds precise anatomical context, helping doctors localize the signal.
GLP-1 medications influence metabolism, insulin production, and gastric emptying. In some patients, these physiological changes appear to alter where FDG accumulates, creating unusual uptake patterns that can obscure true disease signals or imitate pathology.
What the new findings show
Researchers observed a growing incidence of atypical FDG uptake among patients actively treated with GLP-1 agonists. Dr. Peter Strouhal, medical director at Alliance Medical Ltd in the UK, described patterns that were frequent enough to prompt a wider, multi-center review. With no formal international guidance in place yet, imaging teams are navigating this emerging challenge in real time.
Implications for patients and clinicians
The implications are practical and potentially costly. Misreading uptake patterns can lead to unnecessary biopsies or surgeries, improper cancer staging, or missed opportunities for timely treatment. In the United States, roughly one in eight adults report using a GLP-1 medication, a rate that has climbed rapidly in recent years. As usage grows, more scans may present with these unusual appearances.
What doctors are recommending now
Experts stress that patients should not stop GLP-1 therapy before imaging, pending formal guidelines. Instead, clinicians recommend meticulous medical histories and clear documentation of all GLP-1 medications at the time of PET-CT. Radiologists can then interpret scan results with context, distinguishing medication-associated uptake from true disease signals.
The goal is to maintain the benefits of GLP-1 therapies while preserving the diagnostic value of PET-CT scans. As Dr. Strouhal noted, recognizing the characteristic uptake patterns linked to GLP-1 agonists helps prevent unnecessary anxiety and ensures patients receive appropriate care promptly.
What’s next for research and guidance
The research team plans to expand data collection across more imaging centers, bolstering the evidence base for future guidelines. International collaboration is also on the horizon, aiming to standardize interpretations so patients worldwide benefit from consistent PET-CT readings during GLP-1 therapy. In the meantime, healthcare teams are encouraged to document medication use and approach ambiguous scan findings with a cautious, informed mindset.
