DebRD_ATL said:

Steady state is the thing most people miss.

I read this differently from DebRD_ATL, on substance rather than tone. The trial means are being read too generously in this thread. STEP populations were selected, supported, and titrated by protocol, and the real-world curves are consistently a few points worse. That difference is not noise, it is what happens when you remove the study infrastructure.

Happy to go further on any of that.

Adding the numbers, since they settle part of this. 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.

LipidDoc_ATL said:

The trial means are being read too generously in this thread.

Coming at LipidDoc_ATL’s question from a different direction. The shortage clause is the answer to the second question and it is a subtraction rather than an addition. Both exemptions forbid compounding something that is essentially a copy of a commercially available approved product. A product FDA has listed as in shortage is not treated as commercially available, so listing removed the objection that otherwise blocked compounding. It never created a permission; it withdrew a prohibition, which is why it evaporated the moment the supply fact changed.

A narrower follow-up, since the general answer is now clear:

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

Closing the loop on my own question.

Update since I posted: I held at 1.7mg for a further twelve weeks and lost another 4kg slowly, which settles it for me. I was escalating because the number was available, not because I had stopped responding.