This one has a reasonably settled answer, so here it is. 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.

Correct me if the detail matters more than I have assumed.

JessicaH_TX said:

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

Agreeing with JessicaH_TX, and the qualification matters more than the agreement. 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.

tampaLisa73 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…

All true, with one condition: that curve is for people who reached the dose on schedule. Anyone who slowed the ladder for tolerability is on a different, flatter curve, and comparing yourself with the published mean will make you feel like a non-responder when you are not.

Adding the clinical framing, because it changes how the question reads.

tampaLisa73 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.