Needle length selection — January 2024

Taking the question as asked, rather than the general version of it. The trials generally allowed a step to be held or reduced and then retried, and people who did that mostly arrived at the same place a few weeks later. The end point of the ladder is set by tolerability, not by a schedule, and there is no evidence that reaching the top faster produces a better outcome.

CarlaRPh_TPA said:

The trials generally allowed a step to be held or reduced and then retried, and people who did that mostly arrived at the same place a few weeks…

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

sean_dublin said:

Four dose steps in, holding each one the full four weeks, and I am trying to work out whether the interval is a pharmacological requirement or a…

This matches mine closely enough to be worth saying so. Four weeks is the pharmacokinetics, not caution. With a one-week half-life you need four to five half-lives to reach steady state, so at two weeks you are dosing on top of a concentration that has not finished rising. Escalating then stacks exposure and you get the side-effect burden of the higher dose before you have seen the benefit of the current one.

From the other side of the consultation, briefly.

PSA for titration users considering the 0.25mg starting dose: this dose is NOT intended for weight loss. It's a titration dose to let your body adjust. Don't be discouraged if you don't lose much in the first month.

The therapeutic dose for weight management starts at 1.7mg (semaglutide) or 5mg (tirzepatide). Be patient with the ramp-up.