What the maximum dose means

The 15 mg dose marks the top of the licensed schedule. Lower strengths still work for many people. Some adults stay on 5 mg or 10 mg because those maintenance doses give them the right balance of benefit and side effects. Others move up to 15 mg after gradual steps.

The source checked lists no licensed adult Mounjaro dose above 15 mg a week. Do not add extra injections, shorten the gap between doses or combine products to go higher than your prescription. Each of those changes alters how much medicine reaches your body and carries a risk of harm with no tested plan behind it.

What the 15 mg trial result shows

In SURMOUNT-1, people on 15 mg lost an average of 20.9% of their starting weight at 72 weeks in the treatment-regimen analysis. Everyone in the trial had obesity, or overweight with a related health problem, and none had diabetes. They also had lifestyle support and a gradual dose increase at the start.

That figure is an average across the whole course of treatment. Reaching 15 mg does not guarantee further loss. Some people lost less, some lost more and some stopped. Different statistical analyses give different headline numbers, so any result you read should name its study, the people taking part and the time point.

If your weight has stopped changing

A plateau at 15 mg does not mean you need more medicine. Look at how long the plateau has lasted, whether you have taken every dose, and your eating, activity, sleep, other medicines and general health. A stable weight is a good maintenance result if you have already reached your earlier goals.

If the treatment has not helped enough, talk to your prescriber about alternatives and a plan for stopping. NICE and the UK label call for a review when you have lost less than 5% of your starting weight after six months at the highest dose you can tolerate. The decision weighs your own benefits and risks.

Check side effects as well as results

At higher doses your prescriber should still ask whether you can eat enough, stay hydrated and manage day to day. Ongoing vomiting, marked weakness or side effects that keep getting worse need attention, even if reaching 15 mg took months. Time or money already spent is no medical reason to stay on a dose that does not suit you.

Your diabetes medicines may need a review as your blood sugar improves. Raise your blood pressure medicines too if you feel dizzy or get low readings. Do not change these prescriptions yourself. Give the clinician who prescribes them the details so they can adjust the dose safely.

Keeping your treatment going safely

Tell any new prescriber about gaps in treatment before you ask for another 15 mg pen. Restarting after a long break differs from the leaflet's advice on a single missed dose. Coping well with 15 mg before does not mean you can go straight back to the same strength.

The current UK maximum for children and adolescents treated for type 2 diabetes is 10 mg. Do not use adult dosing as a guide for a child. Whatever your dose, you need a reliable prescription, the right device and follow-up you can reach easily.

Sources

Your own medicine leaflet and prescriber come first. A source from another country does not mean the same rule applies in the UK.

  1. Mounjaro UK Summary of Product Characteristics, updated September 2026 medicines.org.uk
  2. Mounjaro UK patient information leaflet medicines.org.uk
  3. SURMOUNT-1: tirzepatide once weekly for obesity pubmed.ncbi.nlm.nih.gov
  4. NICE TA1026: recommendations nice.org.uk
  5. NICE: prescribing, reviewing and stopping tirzepatide nice.org.uk

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