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
Free tracker included with every download this week
NHS Mounjaro Requirements and Access in the UK
If you're considering Mounjaro (tirzepatide) for weight management in the UK, understanding NHS eligibility and the referral pathway is essential. The NHS does provide access to Mounjaro through specialist services, but criteria are strict and regional availability varies significantly. This guide explains exactly what you need to qualify, how the NHS system works, and what alternatives exist if NHS access isn't available in your area. Use our free BMI calculator to check where you currently stand against the eligibility thresholds.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Mounjaro Eligibility Criteria and Referral Requirements
To access Mounjaro through the NHS, you must meet strict eligibility criteria and be referred to a tier 3 or tier 4 specialist weight management service. Standard eligibility requires a BMI of 30 kg/m² or above, or a BMI of 27–29.9 kg/m² with at least one weight-related health condition. Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or previous cardiovascular disease.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS applies lower thresholds starting at BMI 27.5 or above due to higher cardiovascular risk at lower weights. Your GP must refer you to a specialist service — you cannot self-refer. Once referred, the specialist team will assess your medical history, weight loss attempts, lifestyle factors, and suitability for tirzepatide before deciding whether to prescribe. The NHS also requires evidence that you've attempted lifestyle interventions first.
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 Access vs Private Routes: What's the Difference?
NHS route: Free treatment but involves GP referral, assessment by specialist services, and potentially long waiting lists (months to years depending on your region and ICB funding). Mounjaro KwikPen doses are provided at no cost once approved, but availability varies across the country.
Private route: Faster access through online consultations with UK-licensed prescribers. After assessment, a prescription is issued and dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on your dose and provider. Private access is available without NHS referral, though you'll manage the full cost. Our GLP-1 weight loss calculator can help you estimate potential outcomes at different tirzepatide doses to inform your decision-making.
- 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 BMI do I need to qualify for NHS Mounjaro?
You need a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with a weight-related health condition like type 2 diabetes or high blood pressure. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, eligibility starts at BMI 27.5 or above. Use our free BMI calculator to check your current BMI against these thresholds.
How long does the NHS referral and approval process take?
Timeline varies significantly by region and ICB funding. Initial GP referral takes 1–2 weeks, but waiting lists for specialist tier 3 services can be 3–12 months or longer depending on your area. Once seen by the specialist team, approval decisions typically take 2–4 weeks.
Can I get Mounjaro privately without waiting for the NHS?
Yes. Private UK prescribers offer online consultations and can issue Mounjaro prescriptions if you meet eligibility criteria. This typically takes 1–2 weeks from consultation to receiving your first KwikPen. Costs are not covered by the NHS and range from around £129–£320 per month depending on dose.
What's the difference between Mounjaro and Wegovy on the NHS?
Both tirzepatide (Mounjaro) and semaglutide (Wegovy) are GLP-1 based medications approved for weight management. Mounjaro is a dual GIP and GLP-1 agonist; Wegovy is a GLP-1 agonist only. Both follow the same NHS referral pathway and eligibility criteria, though mounjaro vs wegovy availability varies by region.
Does the NHS cover the cost of Mounjaro if I'm approved?
Yes, once approved through NHS specialist services, Mounjaro KwikPen injections are provided free of charge as part of your treatment plan. There are no prescription charges for approved weight management medications through tier 3 services.
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.