The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Mounjaro for Weight Loss on the NHS: Cost, Access & How to Get It
Mounjaro (tirzepatide) is available through the NHS for weight management, but access is through specialist tier 3 weight management services rather than your GP directly. This guide explains how the NHS pathway works, what eligibility looks like, regional variations in availability, and how it compares to private prescription options. Understanding both routes helps you make an informed decision about weight loss treatment in the UK.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
How Mounjaro Access Works on the NHS
Mounjaro is prescription-only and in the UK is accessed through two main pathways. On the NHS, tirzepatide is prescribed within tier 3 (and sometimes tier 4) specialist weight management services, following NICE (National Institute for Health and Care Excellence) approval for certain patients. You cannot obtain Mounjaro directly from your GP — a referral to your local specialist weight management service is required first.
Eligibility for NHS Mounjaro typically requires:
- BMI of 30 or above, OR BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, prediabetes, hypertension, dyslipidaemia, sleep apnoea, or cardiovascular disease history)
- South Asian, Chinese, Black African, or Black Caribbean adults may be eligible at lower BMI thresholds (27.5+)
- Previous attempts at weight loss through diet and exercise (tier 1/2 interventions)
- No contraindications to GLP-1 or GIP receptor agonists
The NHS assessment is comprehensive and personalized — your specialist team will evaluate your medical history, current medications, and suitability before prescription.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS vs Private Access: Cost, Timeline & Practical Differences
NHS access: Free at point of use (prescription charge applies if eligible, currently £9.90 per item in England, or free if exempt). However, waiting lists for specialist tier 3 services vary significantly by region — some areas have waiting times of 6–18+ months. Availability also depends on your Integrated Care Board (ICB) commissioning decisions. Regional variation is substantial; some ICBs fund Mounjaro while others do not.
Private access: Available through online consultations with UK-licensed prescribers. Costs range from approximately £129–£250+ per month depending on dose and provider. Private routes are faster — assessment to prescription typically within 1–2 weeks. You retain choice of dose and can access treatment without waiting lists, but you fund the full cost yourself. Our GLP-1 weight loss calculator can help you compare projected outcomes at different doses.
Before choosing either route, use our free BMI calculator to understand your current category and how eligibility thresholds apply to you. Many people use both tools together to assess whether prescription weight loss treatment is appropriate and what to expect in terms of weight loss alongside dietary and lifestyle changes.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Can I get Mounjaro on the NHS in my area?
Mounjaro is approved by NICE for NHS use, but availability varies significantly by region. Contact your GP practice to ask about referral to your local tier 3 weight management service. Some ICBs commission Mounjaro; others do not. Your GP can check what's available in your area and discuss eligibility criteria specific to your health situation.
How long is the NHS waiting list for Mounjaro?
Waiting times vary widely by region, typically ranging from 3 to 18+ months for specialist weight management assessment. Some areas have shorter waits; others have extensive lists. Ask your GP about current waiting times for your local service when requesting referral. Private routes are faster — usually 1–2 weeks from consultation to prescription.
What's the cost of Mounjaro on the NHS vs private?
NHS Mounjaro is free (or £9.90 prescription charge in England if applicable). Private prescriptions cost approximately £129–£250+ per month depending on dose. The NHS is cost-free but has waiting lists; private is immediate but self-funded. Neither involves ongoing "subscription" — you pay per month or per dose as you take it.
Do I need a GP referral to access Mounjaro privately?
No. Private online consultations are direct with UK-licensed prescribers — no GP referral needed. You complete an online health assessment, the prescriber reviews it, and if suitable, issues a prescription to a GPhC-registered pharmacy. The entire process is independent of NHS services, though your GP should still be aware for safety and drug interaction screening.
Is a weekly weight loss injection better than other weight loss options?
A weekly weight loss injection like Mounjaro (or semaglutide-based Wegovy) is one tool alongside diet and exercise. Clinical trials showed average weight loss of 15–21% body weight over 72 weeks with Mounjaro, though individual results vary. It's most effective when combined with reduced-calorie diet and physical activity. Your GP or prescriber can help determine if it's right for your situation.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.