Mounjaro for Type 2 Diabetes: Dosing and What to Expect
Mounjaro (tirzepatide) is licensed in the UK to treat insufficiently controlled type 2 diabetes in adults and children aged 10 years and over, alongside diet and exercise. Treatment starts at 2.5mg once weekly for four weeks, then increases to 5mg. Adults can move to higher doses if needed and tolerated, up to 15mg weekly, while the maximum for ages 10 to 17 is 10mg. In SURPASS-1, adult HbA1c fell by 1.87 to 2.07 percentage points across the 5mg, 10mg and 15mg doses. Insulin or sulphonylurea doses may need reviewing because combining them with Mounjaro can increase hypoglycaemia risk.
Content last updated: 3 October 2026
Mounjaro (tirzepatide) has separate UK licences for type 2 diabetes and weight management. This guide explains the diabetes licence, dosing, clinical evidence and safety considerations. Happy Pharmacy's Mounjaro weight loss injection service is for eligible adults seeking weight management; treatment specifically for diabetes should be arranged through your usual prescriber or diabetes care team.
Mounjaro's Two UK LicencesMounjaro is licensed to treat insufficiently controlled type 2 diabetes in adults, adolescents and children aged 10 years and over as an adjunct to diet and exercise. It may be used alone when metformin is unsuitable because of intolerance or a contraindication, or alongside other diabetes medicines. Its separate weight-management licence applies to adults who meet the relevant BMI and health criteria. The same medicine is used, but eligibility, treatment goals and clinical monitoring depend on the indication being treated.
The SURPASS Trial Programme: What the Evidence ShowsSURPASS-1: Mounjaro vs Placebo
This 40-week trial studied 478 adults with type 2 diabetes whose blood sugar was not adequately controlled by diet and exercise alone. HbA1c fell by 1.87, 1.89 and 2.07 percentage points with the 5mg, 10mg and 15mg doses respectively, compared with a slight increase on placebo. Between 81% and 86% of participants taking Mounjaro reached an HbA1c target of 6.5% or below. Average body-weight reductions of around 7 to 9.5kg were also observed.
SURPASS-2: Mounjaro vs Injectable Semaglutide
This 40-week head-to-head trial compared Mounjaro 5mg, 10mg and 15mg with semaglutide 1mg in adults taking metformin. All three Mounjaro doses produced greater average HbA1c and body-weight reductions than semaglutide 1mg. These results apply to the doses and population studied and do not mean one treatment is automatically more suitable for every person.
Across SURPASS-1 to SURPASS-5
Across the five core adult trials, Mounjaro produced substantial HbA1c and body-weight reductions in different treatment settings, including use on its own and alongside metformin, SGLT2 inhibitors, sulphonylureas or insulin. The result an individual can expect depends on their starting HbA1c, dose, other medicines, adherence and wider health.
Cardiovascular evidence
SURPASS-CVOT followed 13,299 adults with type 2 diabetes and established cardiovascular disease for a median of four years. Mounjaro was non-inferior to dulaglutide for major cardiovascular events (hazard ratio 0.92; 95% confidence interval 0.83 to 1.01). The UK product information describes this as confirming cardiovascular benefit, although the primary comparison did not establish statistical superiority over dulaglutide.
The licensed starting schedule is straightforward: 2.5mg once weekly for four weeks, followed by 5mg once weekly. If further glycaemic control is needed and the medicine is tolerated, the dose may be increased by 2.5mg after at least four weeks on the current dose. The initial schedule is the same for adults using Mounjaro for weight management, but the treatment goal and the dose chosen for ongoing care may differ. See our Mounjaro dose schedule guide for the complete escalation sequence.
| Dosing step | Adults with type 2 diabetes | Ages 10 to 17 with type 2 diabetes |
|---|---|---|
| Starting dose | 2.5mg once weekly for 4 weeks | 2.5mg once weekly for 4 weeks |
| After 4 weeks | Increase to 5mg once weekly | Increase to 5mg once weekly |
| Recommended maintenance doses | 5mg, 10mg or 15mg once weekly | 5mg or 10mg once weekly |
| Further increases | 2.5mg increments after at least 4 weeks, if needed | 2.5mg increments after at least 4 weeks, if needed |
| Maximum dose | 15mg once weekly | 10mg once weekly |
The 2.5mg dose is used to begin treatment and is not an adult maintenance dose. Do not change the dose without instructions from the prescribing clinician. When Mounjaro is added to insulin or a sulphonylurea, those medicines may need reducing and blood-glucose monitoring is needed to lower hypoglycaemia risk.
How Mounjaro Fits With Other Diabetes TreatmentsMounjaro can be used on its own when metformin is unsuitable, or added to other diabetes medicines. The best combination depends on HbA1c, body weight, cardiovascular and kidney health, hypoglycaemia risk, other medicines and personal preferences.
NICE's 2026 adult type 2 diabetes guidance uses an individualised treatment pathway. It says tirzepatide can be considered as additional treatment for adults living with obesity when initial therapy has been used for at least three months and further treatment is needed to reach the person's glycaemic target. This NHS recommendation is narrower than the medicine's marketing authorisation, so being licensed for type 2 diabetes does not automatically mean it will be suitable or routinely available for every patient.
Nausea, diarrhoea, vomiting and other gastrointestinal effects are the most common problems, particularly while the dose is being increased. In pooled placebo-controlled adult type 2 diabetes trials, gastrointestinal disorders were reported in 37.1% of people taking 5mg, 39.6% taking 10mg and 43.6% taking 15mg, compared with 20.4% taking placebo. Most were mild or moderate. See our Mounjaro side effects guide for warning signs and practical management advice.
Important
Mounjaro has a relatively low hypoglycaemia risk when used alone or with medicines that do not usually cause low blood sugar. The risk increases when it is combined with insulin or a sulphonylurea. Your clinician may reduce those medicines and ask you to monitor blood glucose. Seek urgent help for severe confusion, loss of consciousness or a seizure.
In pooled placebo-controlled adult type 2 diabetes studies, average systolic blood pressure fell by around 6 to 9mmHg and diastolic pressure by around 3 to 4mmHg with Mounjaro, compared with reductions of about 2mmHg for each measure with placebo. These are trial averages rather than guaranteed individual outcomes. Blood pressure, weight, kidney health and lipid levels should be interpreted alongside HbA1c and any treatment side effects.
Monitoring Your ProgressHbA1c is usually checked every three to six months until treatment and blood glucose are stable, and about every six months once stable. Your clinician may also review weight, blood pressure, kidney function, cholesterol, side effects and adherence. Home blood-glucose monitoring is particularly important when insulin or a sulphonylurea is being adjusted, but the appropriate schedule depends on the individual's treatment plan.
Do not reduce insulin, stop another diabetes medicine or change your Mounjaro dose without guidance from the clinician managing your diabetes.
Considering Mounjaro for Weight Management?
Happy Pharmacy provides an online weight-management assessment for eligible adults. This service is separate from prescribing Mounjaro specifically to treat type 2 diabetes, which should be managed through your usual diabetes care team.
View Mounjaro Weight-Loss Treatment → Happy Pharmacy is a GPhC-registered pharmacy (No. 9013192) — Superintendent Pharmacist: Palvinder Deol