Mounjaro Prescribing Guidelines in the UK: the Framework That Decides Who Qualifies

Which set of guidelines actually applies to your situation?

There are two overlapping frameworks at work in the UK, and which one governs your care depends on whether you are accessing treatment through the NHS or privately.

The baseline is always Eli Lilly's licensed prescribing information, derived from the Summary of Product Characteristics (SmPC) approved by the MHRA. Every UK prescriber (NHS or private) must work within it. The SmPC sets the licensed indication (weight management alongside a reduced-calorie diet and increased physical activity), the eligible population (adults with a BMI of 30 or above, or 27 or above with at least one weight-related comorbidity), the dose schedule, and the contraindications that rule out treatment for certain individuals regardless of BMI.

On top of that, NICE technology appraisal TA1026, published in December 2024, adds a layer of NHS-specific criteria, stricter thresholds designed for commissioning purposes rather than clinical licensing. NICE recommends tirzepatide on the NHS for adults with a BMI of at least 35 plus at least one weight-related comorbidity, with BMI thresholds reduced by 2.5 kg/m² for people of South Asian, Chinese, Middle Eastern, Black African or African-Caribbean backgrounds. Private prescribers are not bound by these NHS thresholds (they work to the SmPC) which is why private eligibility is broader than NHS eligibility for this medicine.

The practical decision you face, then, is whether the NHS route is open to you right now, or whether a private regulated pharmacy is the appropriate path. Our overview of GP prescribing of Mounjaro covers the NHS rollout in more detail.

What the dose-escalation rules mean in practice

Mounjaro's prescribing guidelines are unusually specific about how the dose moves upward, and for good reason. The 2.5 mg starting dose exists to give the body time to adjust to a dual GIP and GLP-1 agonist, the gastrointestinal effects that many people notice in the first weeks are considerably better managed when the system adapts gradually. Starting higher is not permitted under the licensed schedule.

After four weeks at 2.5 mg, the prescriber may increase to 5 mg, then 7.5 mg, 10 mg, 12.5 mg, and finally 15 mg, each step requiring at least four weeks at the preceding dose. The key word is "may": a prescriber can hold a patient at a lower dose if side effects are poorly tolerated, and doing so is entirely within the guidelines. The aim is the lowest dose that produces meaningful, sustained results for that individual.

A legitimate service will never jump doses to satisfy a patient's preference or expedite results. At nume, every request to increase a dose is reviewed by a GPhC-registered Independent Prescriber who checks the evidence before approving a change, the same standard the guidelines expect. You can read more about the formal prescribing process on our Mounjaro prescribing page.

The six-month review point matters too. If someone has been on the highest tolerated dose for six months and has lost less than 5% of their body weight, the guidelines indicate that continuing treatment should be reconsidered. This is a clinical threshold, not a commercial one, it protects patients from remaining on a medicine that is not working for them.

Contraindications, cautions, and who the guidelines exclude

The prescribing framework is equally clear about who should not receive Mounjaro, and any service that skips this assessment is not following the guidelines.

Mounjaro is not licensed for people under 18. It is not recommended during pregnancy, while breastfeeding, or for anyone actively trying to conceive. A personal or family history of medullary thyroid carcinoma, or a diagnosis of Multiple Endocrine Neoplasia syndrome type 2, are contraindications set out in the SmPC. Certain gastrointestinal conditions and a history of acute pancreatitis require careful prescriber discussion, the MHRA's clinical guidance on GLP-1 medicines notes that pancreatitis is a known, though infrequent, risk that prescribers and patients should both be aware of.

Interactions also fall within the prescriber's remit. Women using oral contraceptives should be aware that absorption may be affected during the first four weeks of treatment and for four weeks after each dose increase, NHS guidance recommends adding a barrier method during these windows, specific to tirzepatide. Anyone taking other medicines should disclose them fully at consultation.

The guidelines are also relevant if you are considering transferring from another provider. A prescriber is entitled (and in many cases required) to see evidence of your current dose and clinical history before continuing treatment. Our page on getting Mounjaro in the UK addresses what happens if someone has been self-sourcing without clinical oversight.

What a compliant private prescription service looks like

The prescribing guidelines do not distinguish between NHS and private prescribers in terms of clinical standards, only in terms of commissioning thresholds. A private service must still conduct an individual assessment, verify identity and weight, check contraindications, and follow the licensed dose schedule. The difference is that private prescribers can work to the SmPC's broader eligibility criteria rather than NICE's NHS-specific ones.

If you're weighing up whether to go private, the cost context is worth reading, our honest overview of what Mounjaro involves covers what to expect beyond the prescription itself. For a fuller picture of all available treatments, our treatment options page is a good starting point. The clinical guidelines are only as useful as the service applying them: check any online pharmacy on the GPhC register before you proceed.

One thing worth knowing before your consultation: if you order before midday on a weekday and your assessment is approved, dispatch happens the same day, your pen arrives the next working day. That timeline depends entirely on your consultation being submitted in time, so it is worth planning ahead rather than leaving it to the afternoon. When you are ready, start your free consultation and one of our prescribers will review your case the same day.