SarahChen_PharmD said:

Dose-response modeling for tirzepatide: Emax model fitting to the STEP/SURMOUNT dose-finding data shows: Semaglutide: ED50 ≈ 0.6mg, Emax ≈ -18%, Hill…

That is right for the weekly injectables. For the daily agents the interval logic is different and the four-week convention does not transfer.

TirzTom said:

The arithmetic in one line: half-life about a week, so steady state at four to five weeks, so a four-week interval is one steady state per step.

That holds where the measurement is reliable. Where it is noisy — and a lot of what gets tracked here is noisy — the same reasoning produces confident nonsense.

TirzTom said:

The arithmetic in one line: half-life about a week, so steady state at four to five weeks, so a four-week interval is one steady state per step.

Thank you for spelling out the reasoning rather than just the conclusion. Adding it to my notes with a link back to this thread.

Adding the clinical framing, because it changes how the question reads. It helps to ask what evidence would change your mind before you look at any. If nothing would, the discussion is not about evidence, and it is better to say so early than to spend nine posts discovering it.

Moderator note: the sourcing question belongs in the vendor section and has been split out. Tagging this one for the weekly digest.