How a weekly jab builds up
Over about a month. Mounjaro’s product information says its level settles after 4 weeks of weekly doses, and Ozempic’s says 4 to 5. Both peak within a few days of each jab, then fade slowly, so the next lands before the last has gone and the level climbs in steps. Ozempic’s stays about 5 weeks after a last dose.
An estimate from the app’s model
See it build
Drawn from the published models Jabwise uses, for the same dose on time every week. It shows the shape of a build-up, not your own level: bodies and doses differ.
In their own words
From each medicine’s product information, written for prescribers.
| Medicine | Peak after a dose | Half-life | Settled after |
|---|---|---|---|
| Mounjaro | reached 8 to 72 hours post doseMounjaro product information (SmPC) | elimination half-life of approximately 5 daysMounjaro product information (SmPC) | 4 weeks of once weekly administrationMounjaro product information (SmPC) |
| Ozempic | reached 1 to 3 days post doseOzempic product information (SmPC) | elimination half-life of approximately 1 weekOzempic product information (SmPC) | 4–5 weeks of once weekly administrationOzempic product information (SmPC) |
| Wegovy | Not stated | prolonged half-life of around 1 weekWegovy product information (SmPC) | Not stated |
What the numbers say
A few days to peak
8 to 72 hours after a Mounjaro dose, and 1 to 3 days after an Ozempic dose, their product information says.
A month to settle
Mounjaro settles after 4 weeks of weekly doses, and Ozempic after 4 to 5, their product information says.
Weeks to leave
Their product information says about 5 weeks after a last Ozempic dose, 7 after a last 2.4mg Wegovy dose.
Questions
Why does a weekly jab build up?
Each dose fades slowly. Tirzepatide’s half-life is approximately 5 days and semaglutide’s about 1 week, so some of last week’s dose is still there when the next one goes in.
How long does it stay after a last dose?
Ozempic’s product information says semaglutide will be present for about 5 weeks after the last dose, and Wegovy’s says approximately 7 weeks after the last 2.4mg dose. If you’re thinking of stopping, the NHS says talk to your doctor and don’t stop suddenly.
Is the chart my actual level?
No. It’s an estimate from published models of how these medicines behave on average. Jabwise draws the same estimate from your own logged doses, and labels it as one.
Medication level
See your own week in Jabwise.
Jabwise draws the same estimate from your dose history, as a share of your usual peak, and says whether it’s building up, rising or easing. It’s an estimate, never a measurement.
Sources
- Mounjaro product information (SmPC)
- Ozempic product information (SmPC)
- Wegovy product information (SmPC)
- NHS: Semaglutide
- NHS: Tirzepatide
General information, not medical advice. Follow your prescriber’s guidance.
Getting real advice
We’re not doctors. This page sums up what the NHS and the official medicine information say, and can’t tell you what’s right for your body: your prescriber’s instructions and the leaflet in your box come first. More in our terms.
- Quoted from official sources, each one linked
- Sources checked 12 October 2026
- No dosing advice; your prescriber comes first
- A pharmacist, your doctor or NHS 111If you’re not sure how to use your medicine, or a side effect bothers you or won’t go away. NHS 111 if you think you might be having serious side effects, or you’ve used too much.NHS: SemaglutideNHS: TirzepatideNHS 111 online
- Report a side effectAnyone can, not only doctors.Yellow Card (UK)MedWatch (US)