Mounjaro is one of the most talked-about weight loss treatments in the UK right now. But getting it through the NHS isn't as simple as seeing your GP and leaving with a prescription.

GPs can prescribe Mounjaro on the NHS, but only if you meet strict eligibility criteria, and access depends heavily on where you live. The NHS is rolling out tirzepatide (the active ingredient in Mounjaro) over a 12-year period, focusing on certain patient groups first.

So even if you fit the clinical criteria for weight loss medication, you might not qualify for NHS funding yet. This guide explains who can get Mounjaro through the NHS, what the process looks like, and what to do if you don't currently qualify.

Key takeaways

GPs can prescribe Mounjaro on the NHS from June 2025, but only for priority patients meeting specific weight and health criteria

The NHS is rolling out tirzepatide in phases over up to 12 years, so access is limited and varies by region

If you don't qualify for NHS treatment, private prescriptions are available, but you'll need to weigh up costs and what support you'll receive

Most common side effects are digestive (nausea, diarrhoea, constipation). See our side effects guide for management tips

Eligibility criteria for Mounjaro on the NHS

The NHS has set clear requirements for who can get Mounjaro. These look at your BMI (Body Mass Index), any existing health conditions, and your ethnic background (because weight-related health risks vary between ethnic groups).

A checklist infographic showing NHS Mounjaro eligibility criteria: BMI 35+, at least one weight-related health condition, and commitment to lifestyle changes.

BMI requirements

To get Mounjaro on the NHS for weight management, you need a BMI of at least 35. You can check your BMI using the NHS BMI calculator.

If you're from a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background, the threshold is lower at 32.5. This adjustment reflects evidence that people from these ethnic groups often develop weight-related health conditions at lower BMIs.

Your GP will calculate your BMI during your appointment by measuring your weight and height. BMI isn't a perfect measure of health, but it's what the NHS uses to determine eligibility.

Weight-related health conditions

BMI alone isn't enough. You also need at least one health condition linked to your weight. According to NICE guidance (TA1026), qualifying conditions include:

Type 2 diabetes or pre-diabetes
High blood pressure (hypertension)
High cholesterol (dyslipidaemia)
Heart disease or cardiovascular disease
Obstructive sleep apnoea
Non-alcoholic fatty liver disease

Your GP will check your medical records for these conditions. If you have a previous diagnosis, that supports your case. Many people with a BMI over 35 already have at least one of these conditions, sometimes without realising it.

Priority groups during the phased rollout

Because the NHS is introducing Mounjaro gradually, not everyone who meets the basic criteria will get access straight away. During the first phase (the first three years), priority goes to people with:

A timeline diagram showing the NHS Mounjaro rollout phases: Phase 1 (Years 1-3) for highest-need patients, followed by gradual expansion over 12 years.

BMI of 40 or more (or 37.5+ for eligible ethnic groups) and four or more qualifying health conditions
Existing patients in specialist weight management services

The NHS England interim commissioning guidance sets out exactly which groups get priority access and when.

Understanding the NHS prescribing pathway

The NHS has set up specific routes for getting Mounjaro, and they're not always straightforward. How you access treatment depends on whether you go through a specialist service or primary care.

The role of GPs

From June 2025, GPs can prescribe Mounjaro in primary care settings for patients who meet the priority criteria. However, this doesn't mean you can simply book an appointment and walk out with a prescription.

Your GP can:

Assess whether you meet the eligibility criteria
Refer you to a specialist weight management service if needed
Prescribe Mounjaro if you qualify under the primary care pathway
Monitor your progress once you start treatment
Provide ongoing prescriptions

The key difference from previous weight loss medications is that Mounjaro doesn't have to be prescribed through a specialist service. It can be initiated in primary care. However, your local area needs to have the necessary support services in place.

Specialist weight management services

Specialist weight management services (sometimes called Tier 3 services, the NHS term for intensive, multidisciplinary weight management programmes) remain an important route to accessing Mounjaro. These NHS teams provide comprehensive support for weight loss, including dietitians, psychologists, and other specialists.

If you're referred to a specialist service, your assessment will typically cover:

A review of your medical history, including conditions like type 2 diabetes or heart disease
Weight and BMI measurements to confirm you meet the threshold
Blood tests to check for underlying conditions and establish baseline health markers
Discussion of treatment options, including whether Mounjaro is suitable for you

Patients already receiving treatment in specialist weight management services were the first to get access to Mounjaro when the rollout began in March 2025.

Integrated care boards and regional variation

Access to Mounjaro varies significantly depending on where you live. Integrated care boards (ICBs), the local NHS organisations responsible for planning and funding healthcare in your area, decide how and when to implement the rollout.

Some ICBs started prescribing in primary care from June 2025, while others are still developing their services. According to BMJ reporting, fewer than half of ICBs had begun prescribing Mounjaro in primary care several months after the official rollout date.

If you're unsure whether Mounjaro is available in your area, contact your GP practice or check your local ICB's website.

How Mounjaro works

Mounjaro contains tirzepatide, which works differently from older weight loss medications. Understanding how it works can help you decide whether it's right for you.

Mechanism of action

Tirzepatide (the active ingredient in Mounjaro) is a dual GLP-1 and GIP receptor agonist, meaning it works on two appetite-regulating hormones instead of one. It mimics two natural hormones in your body: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). Both hormones are released when you eat and help regulate appetite and blood sugar.

By activating both hormone pathways, tirzepatide:

Slows down how quickly food leaves your stomach, helping you feel full for longer
Reduces appetite signals in your brain, so you feel less hungry between meals
Improves blood sugar control, which is particularly helpful if you have type 2 diabetes or pre-diabetes

A person standing calmly with icons around them showing reduced appetite, slower digestion, and balanced blood sugar – illustrating how Mounjaro works in the body.

Most other weight loss injections (like semaglutide in Wegovy) only target GLP-1. The dual action of tirzepatide appears to result in greater average weight loss.

Weight loss results

In the SURMOUNT-1 clinical trial, participants taking the highest dose of tirzepatide lost an average of 22.5% of their body weight over 72 weeks. To put that in perspective, someone starting at 100kg (about 15 stone 10 pounds) would lose around 22.5kg (about 3.5 stone) on average.

A bar chart comparing average weight loss: Mounjaro showing 22.5% weight loss versus Wegovy showing 15% weight loss over 72 weeks in clinical trials.

The SURMOUNT-5 trial directly compared tirzepatide with semaglutide (Wegovy). Participants taking tirzepatide lost significantly more weight: about 20% of body weight compared to 14% with semaglutide over 72 weeks.

These are averages, and individual results vary. Some people lose more, others less. The medication works best when combined with dietary changes and increased physical activity.

Lifestyle requirements

No weight loss medication works on its own. The NHS expects you to commit to lifestyle changes before and during treatment with Mounjaro.

This typically means:

Following a reduced-calorie diet (your healthcare team can provide guidance)
Increasing your physical activity levels
Attending regular follow-up appointments

Your progress will be reviewed regularly. NICE recommends that if you haven't lost at least 5% of your starting weight after six months on the highest tolerated dose, your healthcare team should discuss whether to continue treatment.

Important safety information

Mounjaro isn't suitable for everyone. There are some situations where you shouldn't use it, and certain health conditions require extra caution.

Who cannot use Mounjaro

You should not use Mounjaro if you are:

Pregnant or breastfeeding
Planning to become pregnant in the near future (stop taking Mounjaro at least one month before trying to conceive)
Under 18 years old
Allergic to tirzepatide or any ingredients in the injection

Health conditions that may rule out treatment

Certain conditions mean Mounjaro isn't appropriate:

Type 1 diabetes. Mounjaro is only approved for type 2 diabetes and weight management, not type 1
Diabetic ketoacidosis, a serious, potentially life-threatening complication of diabetes where the body produces dangerously high levels of ketones (usually requiring hospital treatment)
Personal or family history of medullary thyroid cancer, a rare type of thyroid cancer. Studies in animals showed tirzepatide caused thyroid tumours, though it's not known if this applies to humans
Multiple endocrine neoplasia syndrome type 2 (MEN2), a rare inherited condition affecting hormone-producing glands that increases the risk of certain tumours, including medullary thyroid cancer
Severe kidney problems

If you become pregnant while taking Mounjaro, stop immediately and contact your GP or prescriber. The medication may affect foetal development.

Conditions requiring caution

Some health conditions don't automatically rule out treatment, but your GP should consider them carefully:

Previous pancreatitis (inflammation of the pancreas)
Gallbladder disease or history of gallstones
Severe digestive problems
Diabetic retinopathy (if you have type 2 diabetes)

Your prescriber will weigh up the benefits and risks before deciding whether Mounjaro is right for you.

When to seek urgent medical help

Stop taking Mounjaro and contact your GP or call 111 immediately if you experience:

Severe, persistent stomach pain that doesn't go away (could indicate pancreatitis)
Signs of an allergic reaction: rash, itching, swelling of face or throat, difficulty breathing
Severe nausea or vomiting that prevents you from eating or drinking
Signs of low blood sugar if you have diabetes: shakiness, sweating, confusion, fast heartbeat
Changes in vision if you have diabetic retinopathy

These symptoms are rare but require prompt medical attention.

Ongoing monitoring and support

Getting a prescription is just the beginning. The NHS expects you to have proper support throughout your treatment.

Regular check-ups

While taking Mounjaro, you'll have regular appointments to monitor your progress and check for any problems. These typically include:

Weight and BMI measurements
Blood pressure checks
Blood tests (to monitor blood sugar, kidney function and other markers)
Review of any side effects and how you're managing them
Assessment of whether treatment is working (usually after 3–6 months)

How often you're seen depends on your local ICB's guidelines and your individual health needs. Expect more frequent appointments at the start of treatment, particularly during dose increases.

Wraparound care

The NHS recognises that weight loss medication works best with additional support. Depending on your area, you may have access to:

Dietitian consultations for personalised eating advice
Physical activity programmes or physiotherapy
Psychological support if needed
Regular coaching or check-ins

This "wraparound care" varies by region. Some areas have comprehensive programmes, while others are still developing their services.

Duration of treatment

Unlike some previous weight loss medications, Mounjaro treatment isn't automatically limited to two years. NICE guidance recognises obesity as a chronic condition that may require long-term treatment.

However, your healthcare team will regularly review whether continuing makes sense for you. If you're not losing weight despite taking the medication as prescribed and following lifestyle advice, they may suggest stopping treatment.

What to do next

If you think Mounjaro could help you, here's how to take the next step.

A three-step process showing the path to NHS Mounjaro: book GP appointment, get assessed for eligibility, and either receive prescription or get referred to specialist services.

Book a GP appointment

Start by booking an appointment with your GP. They can:

Check if you meet the eligibility criteria
Assess your weight-related health conditions
Explain what's available in your area
Refer you to specialist weight management services if appropriate

It helps to know your approximate BMI before you go. You can calculate this using the NHS BMI calculator.

If you don't qualify yet

If you meet the basic NICE criteria but aren't in the current priority group, your options include:

Joining a specialist weight management service. Even if you can't access Mounjaro immediately, these services offer comprehensive support for weight loss
Considering other NHS treatments. Your GP can discuss alternatives like Orlistat or referral for bariatric surgery if appropriate
Private treatment. Mounjaro is available through private clinics and online prescribers, though this comes with costs (typically £150–£250 per month depending on dose and provider, see our Mounjaro price comparison) and variable levels of support

If you're using Mounjaro privately, tell your GP. They need to know about all medications you're taking, and it may affect other treatments.

If you're going down the private route, it's worth comparing providers carefully. Pricing, dose availability, and the level of clinical support included differ significantly, so it's worth checking what you actually get for the monthly cost.

Keep track of your health

Whether or not you start Mounjaro, consider keeping a record of:

Your weight over time
Any symptoms or health changes
Questions you want to ask at appointments

This information helps your GP make better decisions about your care.

Frequently asked questions

How long is the waiting list for NHS weight management services?

This varies enormously by area. Some regions have waits of several months, while others have very limited or no specialist services. Your GP can tell you what's available locally and give you an idea of waiting times.

What happens after the NHS prescription period ends?

Unlike semaglutide (Wegovy), Mounjaro doesn't have a fixed two-year limit on NHS prescriptions. Treatment can continue long-term if it's working and you're following lifestyle advice. Your healthcare team will review regularly to decide whether continuing makes sense.

Can I switch from Wegovy to Mounjaro on the NHS?

Possibly, but it depends on your circumstances and local guidelines. If you're currently on Wegovy through a specialist weight management service and meet the criteria for Mounjaro, your team can discuss whether switching is appropriate. Mounjaro has shown greater average weight loss in head-to-head trials, but individual responses vary.

Will Mounjaro affect my other medications?

It might. Mounjaro slows down how quickly food leaves your stomach, which can affect how your body absorbs some oral medications (including the contraceptive pill and some diabetes treatments). Your prescriber will review your medications and make any necessary adjustments.

What are the main side effects?

The most common side effects are digestive: nausea, diarrhoea, constipation, and stomach pain. These usually improve as your body adjusts to the medication. For more details, see our guide to Mounjaro side effects.

How quickly will I lose weight on Mounjaro?

Most people start noticing weight loss within the first few weeks, though it varies. In clinical trials, weight loss continued over 72 weeks. The NHS considers a loss of 0.5–1kg per week to be safe and sustainable, though some people lose weight faster, particularly in the early months.

Can I get Mounjaro if I've had weight loss surgery?

Not usually. NICE guidance recommends Mounjaro for people who haven't had bariatric surgery. If you've had surgery and regained weight, speak to your specialist team about your options.

How does NHS Mounjaro compare to private treatment costs?

NHS Mounjaro is free at the point of use if you qualify. Private prescriptions typically cost £150–£250 per month depending on your dose and provider, plus any consultation fees. The NHS pathway also includes wraparound care (dietitian support, regular monitoring) that may cost extra privately. See our Mounjaro price comparison for current private costs.

How do I actually apply for Mounjaro on the NHS?

There's no formal application process. Book a GP appointment and explain you'd like to discuss weight loss treatment. Your GP will check your eligibility (BMI, health conditions) and either prescribe directly (if available in your area) or refer you to a specialist weight management service. The process varies by region, so your GP can advise on local pathways.

The bottom line

Mounjaro is available on the NHS for weight management, but access is being rolled out gradually over up to 12 years. To qualify, you need a BMI of 35 or above (32.5 for certain ethnic groups) plus at least one weight-related health condition. During the initial phase, priority goes to those with the highest clinical need.

If you think you might be eligible, book an appointment with your GP to discuss your options. They can assess whether you meet the criteria, explain what's available in your area, and refer you to specialist services if appropriate.

For more information on what to expect from treatment, see our complete guide to Mounjaro and our guide to Mounjaro side effects.

Sources

NICE TA1026: Tirzepatide for managing overweight and obesity – National Institute for Health and Care Excellence
NHS England interim commissioning guidance – NHS England
NHS weight management injections information – NHS England
SURMOUNT-1 trial: Tirzepatide once weekly for the treatment of obesity – New England Journal of Medicine
SURMOUNT-5 trial: Tirzepatide versus semaglutide once weekly in patients with obesity01895-3/abstract) – The Lancet
BMJ: Mounjaro rollout progress – British Medical Journal
Mounjaro summary of product characteristics – Electronic Medicines Compendium