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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Understanding Mounjaro Access and Deals in the UK
There's no "deal" on Mounjaro in the traditional sense — it's a prescription-only weight management injection available through NHS specialist services or private prescribing. The cost, eligibility, and route to access depend on whether you pursue NHS or private routes. This guide explains how Mounjaro (tirzepatide) works in the UK healthcare system, who can access it, what it costs, and the real value of this dual GIP/GLP-1 medication for weight management.
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Calculate Your BMI Instantly
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.
NHS Access and Eligibility for Mounjaro in the UK
NICE approval and NHS availability: Mounjaro (tirzepatide) has been approved by NICE for weight management in UK adults and is available through specialist tier 3 and tier 4 NHS weight management services. However, access is limited and varies significantly by region. Your GP cannot prescribe Mounjaro directly — you must be referred to a specialist multidisciplinary weight management service through your local integrated care board (ICB).
NHS eligibility criteria: You may qualify for NHS-funded Mounjaro if you have a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean descent, lower BMI thresholds apply (BMI 27.5 or above). Referral typically follows unsuccessful attempts at weight loss through lifestyle changes or other interventions. Use our free BMI calculator above to check whether you may meet the BMI threshold criteria.
- Referral required from your GP to specialist tier 3 service
- Assessment and prescription through NHS specialist team only
- No direct cost to you (free on NHS)
- Significant waiting lists in many regions — sometimes 6–12 months or longer
- Regional variation in availability and criteria
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 Routes: Cost, Speed, and Eligibility
Private prescribing for Mounjaro: If NHS waiting lists are too long or you don't meet NHS referral criteria, you can access Mounjaro privately through a UK-licensed online prescriber following a clinical assessment. Costs range from approximately £130–£250 per month depending on the dose — a 4-week supply (one KwikPen) covers 4 weekly injections. Private prescriptions can be issued within days to weeks, compared to NHS waiting lists that may extend months.
Real value comparison: The NHS "deal" is free treatment — but with waiting times. The private route costs money but offers immediate access without NHS referral gatekeeping. Both require clinical assessment confirming eligibility (BMI threshold, weight-related conditions, or health risk factors). Use our free GLP-1 weight loss calculator to estimate potential weight loss outcomes at different Mounjaro doses — this can help inform your decision about whether to pursue NHS or private routes.
- 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.
What's the price of Mounjaro on the NHS?
Mounjaro is free on the NHS once prescribed by a specialist tier 3 weight management service. However, NHS access requires a GP referral and assessment through a specialist multidisciplinary team. Waiting lists vary by region; some areas have very long delays. Private routes cost approximately £130–£250 per month depending on dose.
Can my GP prescribe Mounjaro directly?
No. In the UK, GPs cannot prescribe Mounjaro directly. You must be referred by your GP to a specialist tier 3 or tier 4 NHS weight management service, where a multidisciplinary team will assess you. Only after specialist assessment and approval can Mounjaro be prescribed. Private online prescribers can issue prescriptions without NHS referral if you meet clinical criteria.
What's the difference between Mounjaro and Wegovy for UK access?
Both are GLP-1 family weight management injections licensed in the UK, but Mounjaro is a dual GIP/GLP-1 agonist while Wegovy is GLP-1 only. Clinical trial data shows Mounjaro produced slightly higher average weight loss (~21% vs ~15% body weight). Both require prescription and clinical assessment. Accessibility and cost are similar on both NHS and private routes.
How long does NHS Mounjaro take to get?
NHS waiting times vary significantly by region. After GP referral to your local specialist tier 3 service, assessment typically takes weeks to months. In many areas, waiting lists exceed 6–12 months. Private prescribing is much faster — often within days to weeks following online clinical assessment.
Who is eligible for Mounjaro on the NHS in the UK?
NHS eligibility includes: BMI 30 or above, or BMI 27–29.9 with weight-related health conditions (type 2 diabetes, prediabetes, high blood pressure, sleep apnoea, cardiovascular disease). South Asian, Chinese, Black African, and Black Caribbean adults have lower thresholds (BMI 27.5+). Your GP assesses whether referral is appropriate based on your health history and previous weight loss attempts.
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.