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Mounjaro dosage: starting dose, dose increases and missed injections

Treatment guide6 min read·Last updated

Written by Umar Razzaq · Medically reviewed by Nish Fayyaz

A hand holding a pen-style injector device

General information, not individual medical advice. This article cannot take account of your medical history, medicines or circumstances. Speak to a GP, pharmacist or other healthcare professional before making significant changes to what you eat or to any treatment, particularly if you have a medical condition, follow a prescribed diet, take medicines affected by food intake, are pregnant or breastfeeding, or have an eating disorder now or in the past.

Mounjaro is taken once a week. The dose usually starts low and may be increased gradually, giving the body time to adjust and giving the prescriber a chance to review side effects and progress. There is no prize for reaching the highest dose quickly.

The schedule below reflects the current UK product information for adults. Your own instructions from the prescriber take priority.

This page is general information about the licensed schedule. It does not replace your dispensing label or your prescriber's instructions, and it is not a reason to start, stop or change a dose on your own.

A blank weekly planner sheet with a pen

The usual adult dose schedule

StageDose
Weeks 1–42.5 mg once weekly
After four weeksThe usual next step is 5 mg once weekly
Further increasesIf needed, the prescriber can increase by 2.5 mg after at least four weeks on the current dose
Adult maintenance5 mg, 10 mg or 15 mg once weekly
Maximum adult dose15 mg once weekly

The official information sets a minimum interval of four weeks between increases. It does not mean everyone should keep increasing. The appropriate dose depends on response, side effects and the clinician's review. If you are struggling to eat or drink, or side effects are getting in the way of daily life, tell the prescriber before the next increase. The UK product information gives the full dosing instructions.

Why not start high?

Nausea, diarrhoea and vomiting are most likely during dose escalation. A gradual schedule gives time to see how the medicine is tolerated. Increasing the dose is not a way to "break through" a plateau without advice, and a slower increase is not a personal failure. It is a clinical decision about balancing effect and tolerability.

Injection basics

Mounjaro is injected under the skin, not into a vein or muscle. The product information lists the abdomen and thigh as self-injection sites; another person can inject into the back of the upper arm. Rotate the injection site from one dose to the next. The medicine can be taken at any time of day, with or without food.

The KwikPen has its own preparation, priming, dose-selection and disposal instructions. Read the leaflet for the exact pen you have and ask a pharmacist, nurse or prescriber to demonstrate if anything is unclear. Do not try to extract any medicine left in the pen after the four intended doses, and dispose of needles in an approved sharps container. Use the official patient leaflet for the device-specific steps.

A pharmacist advising a customer beside pharmacy shelves

What if I miss a dose?

The UK product information says to take a missed dose as soon as possible within four days. If more than four days have passed, skip it and take the next dose on the regular day. Do not take an extra dose to catch up. If you have missed more than one dose, are unsure when the next dose is due, or have had a longer treatment break, ask the prescriber or pharmacist before restarting.

The weekly day can be changed if there are at least three days between doses. Check the leaflet or ask a pharmacist before changing your routine, especially if you also use insulin or other diabetes medicines.

A simple weekly check-in

Before each dose, check that you have the right strength, the correct day, the product has been stored as directed and you have the supplies needed to inject and dispose of the needle safely. Keep a note of side effects and changes in appetite, hydration, weight and glucose if relevant. Bring that information to reviews. It can help the prescriber decide whether to stay at the current dose, increase, pause or change the plan.

UR

Content Written by:

Umar Razzaq

MPharm | GPhC Reg: 2064448 | University Of Strathclyde

Date Written:

12/06/2026

Role:

Clinical Pharmacist

NF

Medically Reviewed By:

Nish Fayyaz

MPharm | GPhC Reg: 2225257 | University Of Strathclyde

Date Checked:

12/06/2026

Role:

Pharmacist

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Mounjaro Dosage and Dose Schedule: A UK Guide | Lose Weight Fast