A multi-year international study finds that about 10% of people carry PAM gene variants linked to GLP-1 resistance, reducing the effectiveness of GLP-1 receptor agonists like Ozempic for lowering blood sugar in type 2 diabetes.

A Stanford Medicine study published in Genome Medicine identifies a genetic reason for the roughly 10% of people who respond poorly to GLP-1 receptor agonists such as Ozempic and Wegovy, with important implications for diabetes and obesity treatment.

Testing for PAM variants could become a precision medicine tool to identify non-responders early and tailor treatment, though pharmacogenomic testing is not yet standard care.

Clinically, the findings suggest re-evaluating prescribing and monitoring strategies and considering alternatives (like SGLT2 inhibitors or higher-dose tirzepatide) for non-responders instead of continuing ineffective GLP-1 therapy.

Institutions including UT Southwestern and the Texas Diabetes Institute are positioned to translate PAM findings into practice as part of broader diabetes precision medicine efforts.

Two longer-acting GLP-1 receptor agonists showed different results, implying formulation and duration of action may influence responsiveness in PAM variant carriers.

Weight loss data were inconclusive due to limited trial data, and more research is needed to understand how GLP-1 resistance affects weight outcomes.

Researchers emphasize that genetic data from trials could explain varied responses and inform strategies to overcome GLP-1 resistance, including insulin sensitizers or alternative formulations.

Carriers of PAM variants, notably p.S539W and p.D563G, have higher circulating GLP-1 but weaker signaling, leading to reduced drug efficacy.

In PAM variant carriers, higher GLP-1 levels do not translate to stronger glucose control, indicating true pharmacogenomic non-responsiveness.

Clinical trial data show that PAM variant carriers achieved HbA1c targets less often after six months of GLP-1–based therapy (11.5% for p.S539W and 18.5% for p.D563G) versus about 25% in non-carriers, with no impact on responses to other diabetes meds.

Approximately 33 million Americans carry PAM variants, with higher prevalence among people with Type 2 diabetes, suggesting regional and demographic disparities in GLP-1 drug effectiveness.