Half-life

The idea

A medication's half-life is the time it takes for the active amount in your body to drop by half. If something has a five-day half-life, then five days after a dose, roughly half of it is still working; five days after that, a quarter; and so on. Clearance is gradual — there's no cliff where a dose "wears off."

Long half-lives are the reason weekly dosing works at all: the medication is designed to still be active when the next dose lands. They're also the reason levels stack week over week — which is the whole story behind steady state.

What it drives in StaQ

Half-life is the single number behind every curve StaQ draws. Your exposure chart, the active-mg estimate, the steady-state band, the forecast line, and the days-to-steady-state countdown all come from applying your medication's half-life to your actual logged dose history — your real dates and amounts, not an idealized schedule.

That's also why a missed or late dose shows up as a visible dip in the curve: the math is just decay from what you actually logged.

Custom entries

For custom medications and supplements, you can set the half-life yourself. If you leave it blank, StaQ shows your logs as dose events only — no curve — until a half-life is set, rather than guessing. Published half-lives vary by person; the value you (or your prescriber) choose sets how your curves are modeled.