Concentration estimates (ng/mL)

Educational explainer — not medical advice. StaQ's concentration figures are model estimates, not measurements. Only a lab test measures your actual blood levels. Talk to your prescriber before changing anything about your regimen.

From milligrams to ng/mL

StaQ's curves start in active milligrams — how much medication is still working in your body, computed from your logged doses and the medication's half-life. To express that as a concentration (ng/mL, the unit labs and papers use), the active amount has to be divided by a volume: the same milligrams in a larger body sit at a lower concentration.

Where Nadler comes in

That volume comes from the Nadler equation — a long-established formula (1962) that estimates a person's total blood volume from their height, weight, and sex. It's why your profile asks for those fields: they anchor the conversion from active mg to an estimated ng/mL that's scaled to your body rather than a generic average.

It's also why height edits matter more than they look — a changed height quietly shifts the estimated blood volume, which shifts every historical concentration figure computed from it.

What the estimate is good for

The strength of a modeled concentration is comparison over time: how this month's exposure compares to last month's, what a titration did to your plateau, how a missed week looks against a consistent one. The trend and the relative change are far more informative than any single number.

What it is not: a lab result. The model can't see individual absorption, metabolism, or injection-site differences. If you need a true level, that's a blood test — and a conversation with your prescriber.