Switching from Ozempic to Wegovy — January 2024

Short answer first, then the reasoning. The mechanism that matters here is not stomach emptying, it is central. GLP-1 receptor agonism in the arcuate nucleus stimulates POMC neurons and suppresses AgRP/NPY signalling, which is why the effect is appetite and food salience rather than physical fullness. Delayed gastric emptying largely tachyphylaxes over the first months; the appetite effect does not.

Dr.PeteFamMed said:

The mechanism that matters here is not stomach emptying, it is central.

No disagreement with Dr.PeteFamMed. One condition attached. Albumin binding above 99% is the whole reason weekly dosing works, and it is also why the trough matters more than the peak. People who dose late are not losing a peak, they are letting the trough fall, and the appetite effect tracks the trough.

paige_pharma said:

The first four months were close to the trial curve and the last two have been flat, which is roughly what the STEP 1 figure predicts if you read the…

That holds for the injectable. The oral formulation has different absorption behaviour and the dose numbers are not interchangeable, which is worth saying out loud because people quote them as if they were.

From the other side of the consultation, briefly.

paige_pharma said:

...but the FDA says semaglutide...

Interesting point. I want to add some regulatory nuance: the FDA labeling reflects the specific clinical trial data submitted for approval. Real-world clinical practice often extends beyond the FDA label based on emerging evidence and clinical judgment.

Example: semaglutide was first approved for diabetes (Ozempic), then obesity (Wegovy). The molecule didn't change — our understanding of its applications expanded. Similarly, semaglutide may evolve as more data accumulates.