CarlaRPh_TPA said:

The mechanism is more central than most summaries suggest.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Pushing back on the consensus forming here. Consistency is not the same as correctness, and a board that agrees with itself quickly is usually agreeing with the first person who sounded certain.

The figures, for anyone assembling their own picture. Numbers worth memorising for this class: Tmax one to three days for the weekly peptides, terminal half-life about a week for semaglutide and about five days for tirzepatide, steady state at four to five half-lives, subcutaneous bioavailability high enough that site choice is irrelevant.

Worth separating that from the pharmacology, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

NeuroNate said:

Pushing back on the consensus forming here.

Adding the part of the answer the thread has not reached. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

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

Which effects tachyphylax and which persist, because the answer explains why tolerability improves while the appetite effect keeps working?

Reporting back.

Closing this out: the trough rather than the peak explains the pattern I was seeing on day six, which I had been blaming on the vial.