There's an entry most people skip because it doesn't feel like it counts — the week before the first dose. Week zero. The week when nothing has started yet, when there's nothing to log because nothing has happened, when the logging discipline hasn't even begun.
And it's the single highest-leverage entry in the whole journal because it's the only baseline future-you will ever have to compare against. Every entry that comes after dose-day-one is structurally a comparison — week three feels heavier than usual, week six energy is lower than I remember, week ten appetite is back to where it was before — but the comparison only works if there's a recorded version of "before" sitting in the journal. Without week zero, "before" lives only in memory, which is unreliable across months and unreliable across the kind of regimen change that often involves multiple shifts.
Five lines is enough for week zero. Sleep quality this week — average, broken, deep, restless, pick a word. Appetite — normal hunger before meals, snacking between, low-appetite, picked-at-meals.
Energy — steady, fading by afternoon, sharp morning then flat, generally low. Mood — stable, irritable, settled, anxious, neutral. Digestion — regular, sluggish, urgent, unpredictable.
One word per line. Five minutes total. Date it clearly as week zero so it's unmistakable in the chronology — the entry that gets confused with later weeks because the date is missing is no use at all.
Three reasons week zero pays back at every appointment. One — the prescriber asks "is this different from before?" at virtually every appointment after the first few months, and "different" only has meaning if "before" is documented. Without week zero, the answer to that question is a fog of guessed memory rather than a sentence read off the journal.
Two — side-effect attribution improves dramatically. A side effect that started in week three could be the dose, could be coincidence, could be something else entirely. The week-zero entry that documents sleep was already broken before the dose started changes the attribution of week-three sleep notes from "the dose did this" to "the dose may have made the existing pattern worse" — which is a different conversation with the prescriber.
One — the prescriber asks "is this different from before?" at virtually every appointment after the first few months, and "different" only has meaning if "before" is documented.
Three — at month six and month twelve, the question is "am I back near where I started" rather than "am I better than week three" — the recovery curve is always measured against the pre-intervention baseline, not against the worst intervention week. Mechanics. One — if the first dose is tomorrow and there's no week zero entered, write a "best-recollection" baseline entry for the week before, dated and labelled as such, but flagged in the entry itself with one line — "this is a recall entry written on dose-day-one, not contemporaneous" — so future-you knows the entry was reconstructed rather than logged in the moment.
Reconstructed is worse than contemporaneous but better than nothing. Two — week zero is the only entry that benefits from being slightly longer than the discipline of one-line-per-day — five lines covering the five categories is the sweet spot because the baseline needs to be substantive enough to compare against, not so short it's reduced to a single sentence. Three — the week-zero entry is something to read back to the prescriber at the first appointment after starting, not the second or third — the prescriber's first follow-up is the moment the baseline matters most because the dose is still being calibrated.
Organisational note: this is bookkeeping at its most preventative. Future-you in month six will silently thank past-you for writing the entry. The medical interpretation of the comparison — what week-zero versus week-six actually means clinically — is for the prescriber, not for the journal.
Week zero just makes that conversation possible.