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

The concept of "metabolic set point" and its relevance to maintenance dosing: the body actively defends a weight set point through hormonal feedback (leptin, ghrelin, insulin, GLP-1). After weight loss, these signals shift to promote weight regain[1].

GLP-1 agonists may work in part by resetting this set point — or at least overriding the counter-regulatory signals that drive regain. This would explain why continued treatment maintains weight loss while discontinuation leads to regain.

Understanding maintenance dosing through this lens reframes the drug from "weight loss tool" to "metabolic set point modulator."

josh_phd_bmore said:

Dr.Martinez said: ...I stopped maintenance dosing and regained all the weight...

There is a second half to this that has not been said yet. Steady state is the thing most people miss. The terminal half-life is about a week, so every dose step takes four to five weeks to fully express itself. Judging a step at day ten is judging the ascent, not the plateau, and it is the single commonest reason people escalate before they needed to.

Adding the numbers, since they settle part of this. Worth knowing that the injection site changes very little. Abdomen, thigh and upper arm are bioequivalent for semaglutide, so a site change is not a plausible explanation for a bad week.

One thing that is still open after josh_phd_bmore’s answer:

How much of the between-person variation is pharmacokinetic and how much is just adherence measured badly?

Moderator note: the sourcing question belongs in the vendor section and has been split out. No action needed from anybody.