Answer first: the maintenance dose is the lowest one that holds the result, and finding it is a downward search rather than an upward one.
A downward search proceeds one step at a time with at least eight weeks at each level, because a weekly agent takes four to five weeks to reach the new steady state and then needs time for the trend to be readable.
Weekly dosing accumulation, 7-day half-life
| Week | Fraction of steady state | Trough as × dose |
|---|
| 1 | 50 % | 0.50 |
| 2 | 75 % | 0.75 |
| 3 | 88 % | 0.88 |
| 4 | 94 % | 0.94 |
| 5 | 97 % | 0.97 |
| 6 | 98 % | 0.98 |
This is why a four-week step interval is approximately, but not exactly, steady state.
More usefully, the maintenance dose is not necessarily the same a year later, since the counter-regulatory response attenuates slowly if at all.
The counter-regulatory hormonal response to weight loss persists for at least a year after the loss, which is the physiological reason maintenance needs something rather than nothing.
The lowest dose that holds the result is the answer, and it is individual.