Dr.NateNeph said:

Denials are usually procedural rather than clinical, and the order that works reflects that.

Pushing back on Dr.NateNeph here. Guidance here is not settled and varies by institution, so quoting one society's interval as the rule is misleading. The invariant part is disclosure, not the number of days.

Ask again with the specifics and you will get a better answer than this one.

SkepticalSean said:

Elective procedure in five weeks and two different sets of instructions from two different departments about when to stop.

SkepticalSean said:

...surgery and anaesthesia should be combined with bariatric surgery...

This is actually an active area of research. Some bariatric programs are using GLP-1 agonists:

1. Pre-operatively to reduce liver size and surgical risk
2. Post-operatively to enhance and maintain weight loss
3. As an alternative for patients who don't qualify for or want surgery

The combination approach makes physiological sense — surgery addresses anatomy, GLP-1s address neurohormonal signaling. Early data on the combination is promising but we need larger studies.

labquiet_amy said:

Guidance here is not settled and varies by institution, so quoting one society's interval as the rule is misleading.

Timing surgery and anaesthesia around surgery: my surgeon required me to stop GLP-1 agonists 3 weeks before my scheduled procedure due to aspiration risk from delayed gastric emptying.

If you have any upcoming surgeries or procedures requiring anesthesia, TELL YOUR SURGEON AND ANESTHESIOLOGIST that you're on a GLP-1. This is critical for safety.

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

What actually works on a prior-authorisation denial, as opposed to the list of things that sound like they should work?

Reporting back.

Follow-up — getting the denial reason in writing was the step that mattered. It named the criterion, and the criterion was a document I already had.