PharmD_Rodriguez said:

They are two different exemptions from the same federal requirements and they buy different things.

I read this differently from PharmD_Rodriguez, on substance rather than tone. A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to. It is a different legal universe with no pharmacy oversight, no patient relationship and no content guarantee, and conflating the two in these threads helps nobody.

The figures, for anyone assembling their own picture. 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.

amsterdam_pete said:

A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to.

There is a second half to this that has not been said yet. 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.

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

Why a shortage listing created a legal pathway at all, since a shortage is a supply fact rather than a permission?

OP back with an update, since a thread like this is useless without one.

The bulks-list asymmetry was the piece I had missed entirely. It explains why one of my two pharmacies is still arguing it can supply and the other simply stopped.