stretching the interval to 8 or 9 days instead of exactly 7 — smoothing tool or just messing with steady state
See this a lot, usually framed as "saving product" or "spacing it out a bit". Genuinely asking the pharmacology people here: does nudging the interval to 8-9 days meaningfully change anything, or is 7±2 days basically inside the noise floor for a drug with a week-long half-life?
with a roughly one-week half-life, an 8-9 day interval vs a strict 7 is a fairly small perturbation to steady-state levels. not zero, but nowhere near as dramatic as people seem to worry about.
that matches my intuition, good to have it confirmed by someone who actually does this math for a living
the bigger practical risk with stretching intervals isn't the pharmacology, it's habit drift, an occasional 9-day interval becomes an occasional 12-day interval becomes an accidentally missed dose
this is exactly why I never stretch mine even a day, Sunday 8pm every single week, the discipline of the fixed schedule is worth more to me than any theoretical smoothing benefit
honestly this thread is talking me back into just being boring about it and keeping a fixed day, the habit-drift argument is more convincing than any PK argument for stretching