Mounjaro essentials: what to know before you begin

Is Mounjaro actually the right fit for your situation?

Most people researching Mounjaro have already tried the usual routes, lower-calorie diets, more exercise, perhaps an NHS referral that led nowhere. The honest answer is that Mounjaro works well for many people, but it isn't the right fit for everyone, and a prescriber decides that, not a checklist on a webpage.

The licensed criteria are fairly clear. Adults with a BMI of 30 or above can be considered. So can adults with a BMI from 27 upward if they have at least one weight-related condition, high blood pressure, type 2 diabetes, high cholesterol, obstructive sleep apnoea and cardiovascular disease are among the conditions that count. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. What the SmPC doesn't capture is the full clinical picture: other medicines you take, your history, your goals. That's what the prescriber is assessing. You can read more about the evidence base on the Mounjaro weight-loss trials page.

Mounjaro is not recommended during pregnancy, while breastfeeding, or if you're actively trying to conceive. It isn't licensed for under-18s. Certain conditions (including a personal or family history of medullary thyroid carcinoma) require specific discussion before any prescriber can proceed. None of this is meant to put you off; it's meant to make sure the assessment you receive is thorough.

What does the treatment schedule actually involve day to day?

Mounjaro comes as a pre-filled KwikPen. Each pen contains four weekly doses. You inject subcutaneously (into your abdomen, thigh or upper arm) rotating the site each time. The pen stays in the fridge between uses; some people keep theirs in the door next to the milk, which is a perfectly sensible habit as long as it's not near the freezer compartment. For the exact room-temperature window if you're travelling, the Patient Information Leaflet is the authority, not any website.

The schedule starts at 2.5 mg. That first dose isn't designed to produce rapid weight loss, it's there to let your system settle before the prescriber moves you up, typically every four weeks. The licensed strengths run from 2.5 mg up through 5, 7.5, 10 and 12.5 mg, to 15 mg at the top. If you want to understand how the clinical evidence behind these doses was built up, the tirzepatide trials page sets out the key studies and what they found. The NHS tirzepatide medicines page sets out the side-effect profile, storage guidance and contraindications in straightforward language, and it's worth reading before you begin: NHS tirzepatide guidance.

The most common side effects are gastrointestinal, nausea, loose stools, constipation, reflux, burping. They tend to be most noticeable in the first weeks or after a dose step, then ease. Staying well hydrated and eating smaller portions helps most people get through the adjustment period without stopping treatment. If you experience severe, persistent stomach pain that radiates to your back, seek medical attention promptly.

How does the cost and access picture shape your options?

Mounjaro is available on the NHS under NICE TA1026, but the eligibility bar is high and the rollout is phased. As of mid-2026, NHS access requires a BMI of 40 or above alongside four or more of the five qualifying conditions. That threshold will widen in future cohorts, but if you don't meet it yet (or you'd rather not wait) a private prescription through a GPhC-registered pharmacy is the legal alternative.

Private pricing varies by dose and provider. Since Eli Lilly raised UK list prices in September 2025, costs at the higher doses have risen considerably. A Mounjaro price comparison can help you understand what the market looks like and what a realistic, all-in figure should include. One thing worth knowing: legitimate private treatment always bundles a prescription and clinical assessment into the price. If a price doesn't, that's a gap you'll be paying for separately, or a gap you shouldn't ignore.

At nume, the price you see covers the consultation, prescription, the medicine and free next-working-day delivery. There's no subscription, every repeat order goes through a fresh clinical review. We're not positioned as the budget choice, and we don't pretend otherwise.

What should you actually do next?

If Mounjaro seems like a reasonable option after reading this, the next step is a consultation with a prescriber, someone who can look at your health history, current medicines and goals rather than just your BMI. Our clinical team reviews every consultation personally, the same day. There's no algorithm making those calls.

A few practical things worth doing before any consultation: note your current weight (you'll need to verify it on video), gather any relevant medical history, and think about whether you're on oral contraceptives, for tirzepatide specifically, NHS guidance recommends adding a non-oral method for the first four weeks of treatment and for four weeks after each dose increase, because the pill's absorption can be affected. That's not a reason to avoid treatment; it's a reason to go in prepared. If you have questions about how to handle the Mounjaro pen and injections, our guidance covers technique, site rotation and what to do if you miss a dose.

If you'd like to understand more about how the clinical trial data was built, the Mounjaro trials page covers the SURMOUNT programme in detail. And if you have questions that aren't answered here, our support team is available seven days a week. Emerging research on broader health outcomes, including what the evidence currently says about Mounjaro and dementia risk, is something our team keeps a close eye on as the science develops. When you're ready, check your eligibility and start your free consultation.