The Latest on Mounjaro: What the Evidence and Recent Guidance Tell Us

What SURMOUNT-5 actually showed (and why a head-to-head trial matters

For years, comparisons between tirzepatide and semaglutide were indirect) drawn from separate trials with different populations and follow-up periods. SURMOUNT-5 changed that. Published in the New England Journal of Medicine in 2025, it randomised 751 adults with obesity but without type 2 diabetes, following them for 72 weeks. Both medicines were given alongside lifestyle support. Tirzepatide produced a greater average reduction in body weight than semaglutide 2.4mg across the study period.

That finding fed directly into NICE's committee discussion for Technology Appraisal TA1026, which notes that indirect comparisons favour tirzepatide. For anyone reading coverage of GLP-1 results and wondering which numbers to trust, SURMOUNT-5 is the most robust data point currently available for a like-for-like comparison. Dig into the broader evidence picture on the tirzepatide overview page.

One caveat worth holding: trial participants receive close dietary and activity support that doesn't always reflect real-world conditions. Results vary between individuals, and the prescriber's job is partly to help you set realistic expectations before you start.

How the NICE recommendation has developed — and where NHS access stands

NICE's TA1026, first published in December 2024 and updated in September 2025, recommends tirzepatide for adults with a BMI of 35 or above plus at least one weight-related condition. For people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, the thresholds are 2.5 kg/m² lower. NHS England is phasing in access in cohorts: from June 2025, people with a BMI of 40 or above and four or more of five specified conditions (high blood pressure, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, type 2 diabetes) became eligible; Cohort 2, covering BMI 35–39.9 with four or more conditions, activated on 23 June 2026. From April 2026, some GP practices can prescribe under the updated GP contract, though participation is optional and varies by area.

These criteria are strict. Many people who would benefit clinically do not yet meet NHS thresholds, or live in areas where GP prescribing hasn't started. The full Mounjaro guide covers what to do if that describes your situation, including the private licensed route. The latest NHS rollout detail, as it develops, is tracked on the Mounjaro latest news page.

The January 2026 MHRA safety update, what changed and what to watch for

In January 2026 the MHRA issued a Drug Safety Update covering all GLP-1 medicines, including tirzepatide. The update drew attention to acute pancreatitis, not a new finding, but one the regulator wanted patients and prescribers to take seriously. It's infrequent, but it can be serious. The signal to act on: severe stomach pain that comes on suddenly, persists and may spread to the back, with or without vomiting. That pattern warrants urgent medical attention, not a wait-and-see approach.

The more common side effects (nausea, loose stools, constipation, reflux, tiredness) remain a GI-led profile, typically peaking after a new dose and settling within a couple of weeks for most people. The NHS tirzepatide medicines page lists them in full, and it's worth reading before you start. If you ever experience something you're unsure about, the MHRA's Yellow Card scheme at yellowcard.mhra.gov.uk lets patients report directly.

Separately, the contraception note is worth flagging for anyone on the combined pill: for the first four weeks of tirzepatide treatment and for four weeks after each dose increase, adding a barrier method is advisable because gastric slowing can reduce oral contraceptive absorption. Talk to your prescriber about this before you start.

The price increase, and how to think about cost in context

Eli Lilly's September 2025 list price increase was significant. The 15mg pen's list price rose from around £122 to around £330 per four-week pen, and private prices across providers have generally moved upwards since then, typically ranging from roughly £149 to £375 per month depending on the dose and the service. The full picture of what drove that change is covered on the Eli Lilly price increase page, which is worth reading if cost is a primary concern.

When comparing prices between providers, it helps to check what each headline figure actually covers. Prescription fees, consultation charges, aftercare and delivery are sometimes listed separately. At nume, one transparent price includes the consultation, the prescription, tracked next-working-day delivery and access to clinical aftercare seven days a week, no subscription, no auto-renewal. Current treatment pricing is on the treatments page. A registered pharmacy is worth verifying too: the GPhC register entry for nume's pharmacy (registration number 9012878) is publicly searchable.

Mounjaro remains a prescription-only medicine. If you miss your usual injection day, our guidance on taking Mounjaro a day late explains what to do, and a broader look at how late you can take Mounjaro covers the flexibility built into the weekly schedule. If you'd like to find out whether it is clinically suitable for you, our prescribers review consultations the same day and can answer questions specific to your health history.