One concrete data point for the thread. For anyone assembling their own picture: Tmax is one to three days, terminal half-life about 165 to 170 hours, steady state at four to five weeks, and subcutaneous bioavailability near 89%. Those four numbers explain most of the questions people ask about timing.

That is the short version; the long version is somebody else's post.

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

What actually distinguishes 503A from 503B, in terms of what each may make and from what starting material?

TrialTracker_MD said:

For anyone assembling their own picture: Tmax is one to three days, terminal half-life about 165 to 170 hours, steady state at four to five weeks, and…

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.

Happy to go further on any of that.

Reporting back.

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.

LindaRN_retired said:

Albumin binding above 99% is the whole reason weekly dosing works, and it is also why the trough matters more than the peak.

Agreed, and the enforcement dates were staggered by category — 503A first, 503B a few weeks later — because outsourcing facilities have manufactured inventory and clinic contracts to unwind while a 503A makes to order.