Accepted answer
2.4 mg a week is 0.343 mg a day averaged out and 125 mg over a year — but "defensible" is not a property of the number, it is a property of where the number came from. A maintenance dose is defensible when a trial randomised people to it and reported what happened, and indefensible when it was arrived at by interpolation between two doses that were studied. So the question to ask of 2.4 mg is which arm it corresponds to: if a programme ran 2.4 mg as a maintenance level, there is an efficacy figure, a tolerability figure and a discontinuation rate attached to it. If it sits between two studied levels, everything said about it is extrapolation, and the burden of that is on whoever proposed it. The other half of the arithmetic is supply: at 2.4 mg a week a 10 mg vial is 4.17 weeks and you will need about 13 of them a year, which is worth knowing before the dose is settled rather than after. Maintenance doses are set by a prescriber against an individual; nothing here is medical advice.
The relevant observation is that maintenance frequently requires less exposure than the loss phase did, and the trials suggest it rather than establish it.
Maintenance and loss are different endpoints. Loss requires a sustained energy deficit; maintenance requires only that the counter-regulatory drive is offset, and that may need less exposure.
The part that matters: gastrointestinal tolerability generally improves on a reduced dose, which is a genuine quality-of-life argument for the search rather than only a cost one.
STEP-4 and SURMOUNT-4 evaluated withdrawal rather than dose reduction, which is the limit of the direct evidence on this question.
The caveat is that dose reduction is a clinical decision and this is a description of a search strategy rather than a recommendation.
Search downward, one step, eight weeks each, on a rolling average.
edited 10 Aug 2025 by Dr_Colm_Fitzhenry — added a caveat about sampling