GLP-1 Guidelines in the UK: Eligibility, Dosing and Safety (October 2026)

01 · The short version

What are the guidelines for GLP-1 medicines in the UK?

The guidelines for GLP-1 medicines in the UK come from three layers that work together: the medicine's licence, NICE recommendations for NHS use, and the prescriber's own assessment of you. The licence defines who the medicine is approved for. NICE decides who the NHS will fund. The prescriber decides whether it is safe and sensible for you specifically.

For Mounjaro (tirzepatide), the licence says: Mounjaro is licensed for weight management in adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes.¹ It must be used alongside a reduced-calorie diet and increased physical activity.¹

The NHS sets a higher bar because funding is limited. NICE recommends Mounjaro for adults with a BMI of at least 35 plus at least one weight-related condition, and the rollout is phased.⁴ That gap between the licence and NHS funding is why you will see two different sets of numbers quoted, and why neither is wrong. They answer different questions.

02 · At a glance

Licence versus NHS criteria at a glance

A BMI figure is a starting point, not a verdict. A prescriber will assess your BMI, medical history and current medicines before deciding whether it is suitable for you.¹

03 · What to do next

Is this relevant to me, and what should I do next?

If your BMI falls within the licensed range, the practical next step is a conversation with a prescriber, either your GP or a regulated online service. If you are unsure of your BMI, calculate it from your height and weight first, then check whether any weight-related condition applies to you.

If you want to understand the NHS side in more detail, our guide to the NICE criteria for Mounjaro goes through it step by step. Anyone managing diabetes should also read the diabetes pathway, which is separate from weight management.

If you meet the licensed criteria and would rather not wait for NHS access, our weight loss clinic explains the private route. A free online consultation is reviewed by a GPhC-registered prescriber, and unsuitable orders are refunded automatically. As of 10 October 2026, the starting 2.5mg Mounjaro pen has a standard price of £169.99, and all six doses are in stock.

Guidelines describe populations; your prescriber decides for a person.

04 · Which guidelines apply

Which GLP-1 guidelines actually apply in the UK?

Several bodies publish guidance on GLP-1 medicines, and they do different jobs. Mixing them up is the commonest reason people read conflicting eligibility figures online.

The first is the product licence and its Summary of Product Characteristics. This is the legal description of what a medicine is approved for, how it is dosed and what warnings apply.¹ Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly, licensed in the UK for weight management in adults and for type 2 diabetes.¹

The second is NICE, the body that advises on which treatments the NHS should fund and for whom. NICE guidance is about value and priority within a public health service, so its thresholds are tighter than the licence. It includes a practical prescribing guide for clinicians.⁴

The third is the British National Formulary, which clinicians use for day-to-day dosing and safety information.¹¹ It sits alongside the leaflet that comes in the box, which is written for patients.¹³

What about the WHO guideline?

The World Health Organization has also published a global guideline on GLP-1 therapies for obesity in adults. It is a high-level international document, intended to inform national health systems rather than to tell an individual patient in the UK what to do.

What about specialist guidance?

Professional societies publish their own advice for particular situations, such as anaesthesia and surgery. Those documents are written for clinicians and are updated as evidence changes.

How to read conflicting guidance

When two sources seem to disagree, ask what each is for. A licence says who may be treated. NICE says who the NHS will pay for. A prescriber says who should be treated after weighing your history. All three can be correct at once, and a private prescriber works within the licence while taking NICE and the product information seriously.

For a deeper dive into how each document is used day to day, our guide to prescribing guidance explained sets out the clinician's view. Guidance changes, and an old PDF may no longer reflect the latest position.

05 · BMI and eligibility

GLP-1 BMI guidelines: who qualifies?

The BMI guidelines for GLP-1 weight-loss medicines depend on whether you are asking about the licence or about the NHS. Under the licence, Mounjaro is for adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition.¹ The conditions named are high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes and type 2 diabetes.¹

It is for adults, it must be used with a reduced-calorie diet and increased physical activity, and it is not a stand-alone fix. BMI is calculated from height and weight in kg/m². It is a screening number, and your prescriber will look at the wider picture as well.

Ethnic-background adjustments

People from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds are at higher risk of weight- related health problems at a lower BMI, so clinical thresholds are usually reduced by 2.5 kg/m² for these groups.⁴ In practice, that can bring someone into scope at a lower BMI than the headline figures suggest.

If this applies to you, say so in your consultation. It is a recognised part of clinical assessment, not a loophole, and a prescriber will take it into account alongside your health history.

What the NHS asks for

On the NHS, NICE recommends Mounjaro for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁶ Full rollout is expected to take years.⁶

That means you can meet NICE's threshold and still be waiting, because access is released in stages. Ask your GP surgery or local weight-management service where your area is in the rollout.

What are the requirements to qualify for GLP-1?

In plain terms, you need to be an adult, fall within the BMI range for the route you are using, have no reason in your medical history that makes the medicine unsuitable, and be willing to combine it with diet and activity changes. A prescriber confirms all of this.

They will check your BMI, medical history and current medicines before deciding whether it is suitable for you.¹ Be honest on the questionnaire. Leaving out a past pancreatitis episode or a family history of thyroid cancer undermines the very safety checks that protect you.

If your BMI is just outside the range, the answer is not to adjust a number. A prescriber can discuss other support with you, and our weight loss clinic page outlines the options.

06 · NHS versus private

NHS guidelines for GLP-1 versus private prescribing

The NHS and private routes follow the same medicine and the same safety rules, but they differ in who is eligible and how quickly. Mounjaro is available on the NHS, but access is being phased in over several years.⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.⁶

What the NHS route looks like

NHS treatment is driven by NICE's recommendation and the NHS England rollout plan. Eligibility is narrower, and the highest-need groups are prioritised first. Treatment is usually delivered through primary care or specialist weight-management services, depending on where you live.

The benefits are clear. There is no medicine cost beyond any standard prescription charge, and care sits within your existing health record. If you are in England, the NHS prescription charge is £9.90 per item, though exemptions apply and a prescription prepayment certificate may be cheaper for frequent users.

The drawback is waiting. Because rollout is staged, someone who meets the criteria on paper may not yet be offered treatment locally.

What the private route looks like

Private treatment follows the licence, which is wider than NHS criteria. You complete a health questionnaire, a GPhC-registered prescriber reviews it, and the pharmacy dispenses if you are suitable. That is the approach we take: a free online consultation, a prescriber review rather than a scoring script, and automatic refunds for unsuitable orders.

Ongoing care matters as much as the first order. Our service includes monthly reviews, dose-titration and follow-up assessments by the prescribing team, and repeat orders re-check suitability. There is no auto-shipping and no subscription.

Cost, honestly

Private treatment costs money, and the cost depends on the dose you need. At standard prices, if you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96. A first year costs £2,711.88 if you settle at 5mg, up to £3,599.88 at 15mg. These are before discounts: a new customer's first order is £40 less with code FIRST40, and every later order is £25 less (code DOSE25).

Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £339.00 per month across all doses as of 10 October 2026, so it is worth comparing like with like before you choose.

Which should you choose?

If you meet NHS criteria and your area is offering treatment, the NHS is a sensible first call. If you meet the licensed criteria but not the NHS ones, or you cannot wait, a regulated private service is a legitimate alternative. Check any provider on the GPhC register; ours is registered under number 9012878. Our wider Mounjaro guidelines page covers both routes side by side.

07 · Dosing guidelines

GLP-1 dosing guidelines: how Mounjaro is titrated

Mounjaro dosing is a stepped ladder designed around tolerability, not speed. Everyone starts Mounjaro on 2.5mg once a week.¹ This starting dose is about letting your body adjust, not about weight loss itself.¹

After at least 4 weeks the dose increases to 5mg, and can then step up by 2.5mg at a minimum of 4-week intervals (7.5mg, 10mg, 12.5mg) up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹ Many people settle at a maintenance dose of 5mg, 10mg or 15mg — higher is not automatically better, and your prescriber will guide the right pace.¹

How the injection works

Mounjaro is injected under the skin (subcutaneously) once a week, on the same day each week, at any time of day, with or without food.¹ Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection.¹³ Rotate the site with each dose. Each KwikPen contains four weekly doses.¹³

The pen is set by turning the dose knob until the dose indicator shows the correct dose in the window.

Timing, missed doses and changing day

There is no best time of day. Mounjaro works the same morning or evening, with or without food, and what matters is the same day each week.¹³ Many people choose a weekend morning so early side effects fall on days off.

If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time, then carry on with your usual day.¹³ If more than 4 days have passed, skip the missed dose entirely and take the next one on your normal day — never take two doses within 3 days of each other.¹³

You can change your weekly injection day if needed, as long as at least 3 days (72 hours) have passed since your last dose.¹³

Other GLP-1 medicines

Dosing differs by product. Wegovy (semaglutide) uses a ladder of 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg once weekly, with titration stepping up after at least four weeks and reaching the 2.4mg maintenance dose from week 17. Liraglutide products such as Saxenda are supplied at 6mg/ml and are a daily injection, unlike once-weekly Mounjaro and Wegovy. Never apply one product's schedule to another. For Mounjaro specifics, our Mounjaro-specific prescribing rules go further, and you can compare the Wegovy pen on its own page.

08 · Safety and warnings

Safety guidelines: dangers, warnings and who should not take GLP-1

GLP-1 medicines are well-studied prescription treatments, but they are not risk-free and not right for everyone. Understanding the main cautions helps you answer a consultation honestly and spot problems early.

Who should not take Mounjaro

Mounjaro is not suitable for everyone.¹ You should not take it if you are allergic to tirzepatide or any of its ingredients, and it should not be used during pregnancy or while trying to conceive.¹ Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive. If you become pregnant during treatment, stop the medicine and tell your prescriber promptly. Your prescriber will take extra care, or may recommend against treatment, if you have a history of pancreatitis, severe gut or digestive disease, diabetic retinopathy, or gallbladder problems.¹ Always share your full medical history and medicine list during consultation.

What is the black box warning for GLP-1?

'Black box warning' is a US labelling term. The relevant UK information is the thyroid safety statement. In rodent studies tirzepatide caused thyroid C-cell tumours; it is not known whether this applies to humans, and no increase has been shown in human trials.¹

As a precaution, tell your prescriber if you or a close relative have had medullary thyroid cancer or the inherited condition MEN 2 — they will weigh this in your assessment.¹ Routine thyroid monitoring is not required for most people.¹

Everyday side effects

Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹³ Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.

If something worries you, contact your prescriber or pharmacy rather than waiting.

Contraception and other medicines

The medicine can reduce absorption of oral contraceptives because stomach emptying slows.⁷ The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹ Ask your prescriber what contraception approach suits you. If you take insulin or sulfonylureas, doses may need adjusting because of the risk of low blood sugar; this is a conversation for your diabetes team, not a reason to avoid treatment automatically.

What does GLP-1 do to your face?

Facial changes are not a listed side effect in the product information (SmPC and leaflet). Losing a significant amount of weight quickly can change facial volume on any method, including diet or surgery, so discuss any concerns with your prescriber. If you notice any new symptom you are concerned about, discuss it with your prescriber and report it through the Yellow Card scheme.¹⁹

Counterfeit and unregulated supply

Be wary of anyone offering to supply without a consultation or prescription. Counterfeit pens have been the subject of MHRA alerts.⁷ Check any pharmacy on the GPhC register. Our Mounjaro comes through official LillyDirect supply, direct from Eli Lilly's UK distribution, and every pen is a genuine KwikPen.

Is taking a GLP-1 worth the risk?

That is a personal judgement that belongs with you and a prescriber who knows your history. The honest framing is benefit against risk: the potential benefits in trials are substantial for many people, the main cautions are well characterised, and a proper assessment screens for the situations where risk outweighs benefit. If you are unsure, say so in your consultation and ask for the reasoning to be explained.

09 · Nutrition and results

Nutrition guidelines and realistic results

GLP-1 medicines are licensed as an aid to diet and activity, never a replacement for them. Mounjaro is used alongside a reduced-calorie diet and increased physical activity.¹

How the medicine supports eating changes

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1.¹ Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin.¹ In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

This dual action is what distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide (Wegovy/Ozempic).¹ For meal planning, ask your prescriber or a registered dietitian for advice tailored to your health.

What the headline trial found

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² These are trial averages — individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight.² Half of participants on 10mg and 57% on 15mg lost at least 20% of their body weight.² As a worked example only, for someone starting at 100 kg, 20.9% is about 21 kg, but trial averages do not predict your own result.

The realistic pace

Weight loss on Mounjaro is gradual by design.¹ The first weeks on 2.5mg are an adjustment phase and losses are usually modest; most measurable progress builds from 5mg onward, month by month. Trials measured results at 72 weeks — think in months, not days, and judge progress by trend, not individual weigh-ins.

The 2.5mg starting weeks are about adjustment, and experiences differ widely: some people notice appetite change and early loss in week one, others feel little until a higher dose — both are normal.¹ Early loss includes water weight, so the trend over weeks matters more than any single weigh-in.

How your response is reviewed

Treatment response is reviewed by your prescriber: if you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.¹ That is the practical continuation rule behind the 'stopping' guidance often quoted online. It is a discussion point, not an automatic cut-off, and it is one reason ongoing reviews matter.

Track your progress in whatever way works for you. Our free GLPTrackr companion app (iOS and Android) lets you log your journey and spot trends rather than reacting to a single day's reading.

10 · Storage and travel

Storage, travel and practical guidelines

Mounjaro pens need to be kept cold until you start using them, and the rules change once a pen is in use. Getting this right protects the medicine's potency and your safety. Keep Mounjaro pens in a fridge at 2–8°C and never freeze them.¹

Once in use, a pen can be kept out of the fridge at a temperature not above 30°C for up to 30 days after first use — useful for short trips — and must then be thrown away. Do not use a pen that has been above 30°C. Keep the pen cap on to protect it from light, and never use a pen that has been frozen.¹

Unopened pens

Unopened pens should be kept in the fridge and keep until the expiry date printed on the box.¹³ If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit — figures circulating online often come from other countries' labels.¹³ UK KwikPens follow the UK product information, so use that as your reference.

Travelling with Mounjaro

You can fly with Mounjaro.¹³ Carry pens in hand luggage (hold luggage can fall below freezing), ideally in a cool bag with the prescription label or a copy of your prescription.

In-use pens tolerate up to 30 days not above 30°C, so most holidays need no special arrangements; for hot climates use an insulated pouch. Check destination rules for travelling with prescription injectables before you fly.

Surgery, sedation and anaesthesia

People often ask about GLP-1 anaesthesia guidelines. Professional bodies publish guidance for clinicians on how these medicines are handled around procedures that involve sedation or general anaesthesia. Because the medicine slows how quickly the stomach empties, the teams looking after you will want to know you take it.

The practical rule is simple: tell the surgical, endoscopy or anaesthetic team that you use a GLP-1 medicine well before the date, and follow their instructions about your doses. Do not decide for yourself to skip or change doses.

Stopping treatment

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system — there is no way to speed this up, and nothing needs doing while it clears.¹ Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average.¹⁴ If you are thinking of stopping, talk to your prescriber first so they can support you through it and review next steps.

Getting help

If you have a question about storage, a damaged pen or a side effect, contact support Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, through the account portal chat or by phone on 0333 207 0413. Needles, a sharps bin and injection guidance are included with every order.

11 · Getting treated safely

How a regulated GLP-1 prescription works step by step

A properly regulated GLP-1 prescription follows a fixed order: assessment first, supply second. Knowing the steps helps you tell a safe provider from a risky one.

Step one: free online consultation

You complete a short health questionnaire. It is free, with no charge and no obligation. The questions cover the things guidelines say matter: your BMI, any weight-related conditions, your medical history and your current medicines.¹ Answer fully and honestly, because the answers decide what is safe.

Step two: prescriber review

Your answers are reviewed by a GPhC-registered prescriber, not a scoring script. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full. If it is suitable, the prescriber confirms the starting dose, which for Mounjaro is always 2.5mg.¹

Step three: dispensing and delivery

Approved prescriptions are dispensed by our registered pharmacy, with same-day dispatch when ordered by 3pm. Delivery is free, next-day and tracked with DPD, in temperature-controlled, discreet packaging. Saturday delivery is £14.99.

Ongoing care

Guidelines expect treatment to be reviewed, not left on autopilot. Our prescribing team runs monthly reviews, dose-titration and follow-up assessments, and offers side-effect support. Repeat orders re-check suitability, and nothing ships automatically.

Paying and discounts

You can pay by Visa or Mastercard, Klarna or pay-monthly options, with no subscriptions. New customers save £40 on their first order with code FIRST40, and an automatic £25 reorder discount applies to every future order (code DOSE25). The price shown is the price paid, with no hidden fees.

More than 100,000 customers have been supported on their weight loss journey with us, and that figure describes how many people we have served, not how well the medicine will work for you.

Ready to see if you qualify? Start from the Mounjaro pen page, where the live prices and consultation are in one place.