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Prescribed by UK Doctors. Dispensed by Registered Pharmacists.

Treatment information

Mounjaro

Tirzepatide. Dual GIP and GLP-1 receptor agonist. This page explains the medicine; it is not a product page, price list or checkout.

Dual GIP and GLP-1 receptor agonistPrescription-only medicine

How it works

How Mounjaro is used

Tirzepatide acts at two gut-hormone receptors, GIP and GLP-1. These hormones are involved in appetite and satiety, so the medicine can reduce appetite and how much you eat.

Licensed weight-management context

UK product information authorises tirzepatide for adult weight management, alongside a reduced-calorie diet and increased physical activity, at an initial BMI of at least 30, or BMI 27 to under 30 with at least one weight-related condition. This describes licensed use; it does not oblige a private prescriber to prescribe.

Key considerations

What a clinician needs to know

This is not a full medical history checklist. It shows the kinds of information that change whether a medicine is appropriate and how it is monitored.
  • A history of pancreatitis, gallbladder problems, or severe stomach and gut conditions.
  • Diabetes treatment, especially insulin or sulfonylurea medicines, which may need adjusting.
  • Kidney or liver disease, and any recent dehydration or persistent vomiting or diarrhoea.
  • A history of an eating disorder, or any current concern about disordered eating.
  • Pregnancy, breastfeeding, or plans to become pregnant.
  • Any surgery, procedure or sedation planned, because the team needs to know you use this medicine.

Common effects

Effects that are commonly reported

Side effects are usually worst during dose increases, and can be managed by adjusting the plan with a clinician.
  • Nausea, vomiting, diarrhoea, constipation and abdominal discomfort are common, especially when the dose is increased.
  • Dehydration caused by these effects can lead to more serious complications.
  • Gallbladder disease, serious allergic reactions and low blood sugar in some situations are recognised risks.

Safety context

Current safety information

Medicine information changes. These points are based on the current UK sources listed at the end of this page.

Important safety information for Mounjaro

  • Severe, persistent abdominal pain that may spread to the back, sometimes with nausea or vomiting, needs urgent medical attention because of the risk of pancreatitis.
  • Tirzepatide can reduce how well oral contraceptives work. Current UK product information advises adding a barrier method, or switching to a non-oral method, for four weeks after starting and after each dose increase.
  • Supply must come through an authorised prescriber and pharmacy because falsified medicines are a real risk.

Medicine-specific considerations

What is different about this medicine

  • Dose changes are made by a prescriber and are not a self-service decision.
  • The starting dose is built up gradually to limit side effects.

Clinical decision

How a decision is made

No result is automatic. A prescriber decides with you whether a medicine is appropriate, and may recommend more information, a different treatment, or a different next step entirely.

Dose changes are a clinical decision

Starting, increasing, pausing or stopping a medicine is overseen by a prescriber. All treatment is subject to clinical assessment. Results vary between people and are not guaranteed.

Sources

Where this information comes from

Foundation content, reviewed September 2026. It is not yet approved clinical content for this service, and medicine information can change.

Is Mounjaro right for you?

An eligibility check is an initial step, not a prescribing decision. A clinician reviews your information before any treatment is considered.
Check your eligibilityCompare treatments

All treatment is subject to clinical assessment. Results vary between people and are not guaranteed.