NeuroNate said:

The pharmacokinetics explain nearly every practical question asked here.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. The "earlier than weight loss explains" argument is weaker than this thread makes it sound. Blood pressure and inflammatory markers move fast and are downstream of early weight loss, so the mechanism is not as cleanly separable as the summaries imply.

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.