Tirzepatide in type 2 diabetes: the SURPASS programme, summarised honestly

Tirzepatide in type 2 diabetes: the SURPASS programme, summarised honestly — setting out what I have, and where I think it stops being reliable.

I have spent a fortnight trying to pin tirzepatide in type 2 diabetes down and I want to set out where I have got to, because I suspect the honest answer is duller than the thread this will produce.

What I have: a consistent observation across a small number of cases, collected the same way each time. What I do not have: any controlled comparison, or any reason to think my cases are representative.

The specific question is whether the pattern survives once the obvious confounder is removed. I cannot remove it with what I have.

This follows post #42 rather than contradicting it.

Titration schedules for tirzepatide have more dose steps than semaglutide partly because the compound is more potent and partly because the clinical programme used a finer gradation. That does not mean you cannot escalate on a coarser schedule if that suits you — the published schedule is not a lower bound.

Mass and charge states: tirzepatide is about 4813.5 Da and on an electrospray instrument you would expect to see charge states mostly in the 2+ to 4+ range, the same as semaglutide. A doubly charged species would appear at about (4813.5 + 2 × 1.008) / 2 ≈ 2408.

Worth checking against a second source before it gets quoted onward.

Confirming post #56 from a second method, which matters more than confirming it from a second person.

Tirzepatide's half-life of roughly five days means steady state is approached in about three weeks rather than four. That is a real difference from semaglutide and it is small enough that the weekly schedule is unaffected.

Reading it again, the caveat matters more than the finding.

Post #63 describes the usual case. This is about the unusual one.

An honest declaration on tirzepatide in type 2 diabetes: I have a prior here and it is strong enough that you should weight what I say downward. Stating it rather than hiding it.

On post #111 — agreed on the reasoning, with one qualification.

Two things can be true about tirzepatide in type 2 diabetes at once: the mechanism is plausible and the evidence for the size of the effect is thin. Most of the argument here is people defending the first against attacks on the second.

On post #155 — agreed on the reasoning, with one qualification.

Checked the tirzepatide in type 2 diabetes claim against the primary source this morning. It survives, with a narrower scope than the version quoted here. Posting the narrower scope.

That is clearer than the version I had in my head. Thank you.