Ozempic Half-Life and Pharmacokinetics, Straight From the FDA Label

This is a reference page. Its only job is to reproduce, accurately and with attribution, the pharmacokinetic statements that appear in the FDA-approved United States prescribing information for Ozempic, so that someone keeping a personal medication record can see the provenance of the numbers they encounter.

It is not medical advice. It has not been written or reviewed by a clinician, and it makes no recommendation about whether any medication is appropriate for anybody. It does not tell you how much to take, when to take it, or when to change anything. Those decisions belong to the person who prescribed your medication, working from your individual situation, which a web page cannot see.

If you are looking for guidance rather than reference material, the right next step is a conversation with your prescriber or pharmacist, not a page like this one.

All pharmacokinetic figures on this page come from one document: OZEMPIC (semaglutide) injection, for subcutaneous use — the United States Prescribing Information published by Novo Nordisk and approved by the FDA. The pharmacokinetic statements sit in Section 12.3, Pharmacokinetics, within Section 12, Clinical Pharmacology.

The copy consulted for this page was read on DailyMed, the National Library of Medicine's mirror of current FDA-approved labeling, accessed 1 September 2026. The label records an Initial U.S. Approval of 2017.

Labels are revised. A prescribing information document is a living regulatory artefact, and the version you read next year may differ from the version quoted here. That is exactly why the access date is printed alongside every figure rather than buried in a footer. If a number here ever conflicts with the current label, the current label wins.

The prescribing information states, in Section 12.3, that the absolute bioavailability of semaglutide is 89%.

Absolute bioavailability is the fraction of an administered dose that reaches systemic circulation unchanged, expressed against an intravenous reference. A figure of 89% is high, and it is characteristic of a subcutaneous peptide designed for slow, near-complete absorption from the injection site.

This number matters for anybody trying to reason about how injectable and oral forms of the same molecule compare. Semaglutide is available both as a subcutaneous injection and as an oral tablet, and the difference between them is overwhelmingly a difference in absorption rather than a difference in the molecule. Any comparison that ignores bioavailability will be wrong by a large multiple.

The label states that maximum concentration of semaglutide is reached 1 to 3 days post dose.

It is worth dwelling on the form of that statement. The label gives a window measured in days, not a point estimate measured in hours. Reference tables and tracking tools frequently convert this into a single figure — 48 hours is a common choice, being the middle of the range — and that conversion is a modelling decision made by whoever built the table, not something the FDA-approved label asserts.

When you see a precise time-to-peak value for semaglutide anywhere, including inside an app, the honest description of it is "a working midpoint drawn from a labeled range of 1 to 3 days." Treating it as a measured property of your own body would be a mistake.

Section 12.3 states that semaglutide has an elimination half-life of approximately 1 week, and that with that half-life, semaglutide "will be present in the circulation for about 5 weeks after the last dose."

The second half of that sentence is the part most people miss. A one-week half-life does not mean the medication is gone after a week. Half-life describes the time for concentration to fall by half; repeated halvings take a long time to approach zero, which is why the label puts a roughly five-week figure on residual presence.

The same property explains why the label describes steady state as being reached following 4 to 5 weeks of once-weekly administration. Levels accumulate across several doses before flattening out. For somebody keeping records, this is the single most useful fact on the page: what you feel in a given week is not a clean readout of the dose you took that week.

Ozempic is escalated gradually rather than started at a maintenance level, and the prescribing information describes that escalation in its dosage and administration section.

This page does not reproduce it. Not because the information is secret — it is in a public document that anybody can read — but because a titration schedule is only meaningful attached to a specific person, and a page that publishes one invites readers to follow it. Escalation timing gets individualised constantly: for tolerability, for other medications, for clinical circumstances that no reference page knows about.

So the honest framing is the one this page uses throughout. A stepwise schedule exists. It is defined in the label and individualised by your prescriber. Your job, and the job of a tracking app, is to record accurately what was actually prescribed and actually taken — never to generate a plan.

GLP-1 Tracker treats a medication like Ozempic as a record-keeping problem, which is the only kind of problem an app is qualified to solve here.

What it records is what you enter: the date of each dose you log, the injection site you noted, weight and BMI entries you add over time, meals captured through the photo scan with calories, protein and fiber estimated, and any notes you want to keep about how a week went. It holds those things together in one timeline instead of scattered across a notes app, a paper diary and memory.

What it does not do is decide anything. It does not evaluate whether your routine is working, it does not flag anything as clinically significant, and it does not generate schedules. The value is entirely in having an accurate, complete record when somebody qualified asks you what has actually been happening.

GLP-1 Tracker includes an educational medication-level view that draws a curve from the doses you have logged and a published half-life figure of the kind quoted on this page.

It is a teaching illustration and nothing more. It is built from population-level label figures, not from you. It cannot account for your body weight, your kidney function, injection-site variation, adherence gaps, or the ordinary biological variability between two people given identical doses. It is not a measurement, it is not a blood level, and it is not a clinical reading.

The legitimate use of a curve like that is intuition: seeing why a weekly medication accumulates over the first month, or why a missed dose does not produce an immediate cliff. The illegitimate use is treating it as information about your own body, or letting it influence a dose. It should never do either.

The practical reason to care about any of this is the appointment. Prescribers work from what you can tell them, and most people reconstructing several weeks from memory get the details wrong in exactly the ways that matter — which week a dose was missed, when a symptom started relative to a change, whether weight moved before or after.

A log fixes that, and it does so without needing to be clever. Dates, sites, weights, meals, notes. Accurate and boring beats interpreted and confident every time.

What you should not bring is a conclusion drawn from a reference page or an app chart. Bring the record; leave the interpretation to the person who is qualified to do it and who knows your history. That division of labour is the whole point of this pillar.