NIH Finds Mechanism Behind Ozempic Weight‑Loss Plateau
SkimNews Take
The drug's diminishing effect is not due to the body adapting to weight loss, but to the brain's internal signaling mechanism for the drug itself becoming less efficient over time.
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- NIH researchers used fluorescence imaging in live mouse brain tissue to track semaglutide’s effect on neurons, revealing cAMP signaling changes in the area postrema.
- Semaglutide triggered cAMP elevations that varied across individual neurons, with some maintaining prolonged signals while others showed only brief spikes.
- Area postrema neurons displayed heterogeneous cAMP responses, and some reduced signaling by internalizing GLP‑1 receptors, contributing to waning drug efficacy.
- Roflumilast, a PDE4 inhibitor, shifted more neurons toward longer lasting cAMP signaling, demonstrating that the signal can be prolonged.
- Andrew Lutas, NIH NIDDK investigator, said the work explains why GLP‑1 drugs such as Ozempic and Wegovy often plateau, opening avenues for combination therapies.
Why it matters: Patients using Ozempic or Wegovy may maintain weight loss longer, cutting obesity‑related healthcare costs for insurers and giving pharma a path to extend drug efficacy with adjunct PDE4 blockers.
