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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NHS Criteria For Mounjaro — UK Eligibility Requirements
Getting Mounjaro on the NHS in the UK requires meeting specific eligibility criteria set by NICE and your local integrated care board (ICB). Generally, you need a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Access is through specialist tier 3 weight management services, not standard GP prescription. Eligibility varies by region, and waiting lists can be substantial. Your GP can refer you to your local specialist weight management service for assessment.
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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 Mounjaro Eligibility vs Wegovy — Key Differences
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) have similar NHS eligibility criteria, but they work differently. Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy is a GLP-1 agonist only. In clinical trials, Mounjaro users achieved average weight loss of around 20.9% at the maximum 15 mg dose, whereas Wegovy users achieved approximately 14.9% at the maximum 2.4 mg dose — though individual results vary significantly.
- Both require BMI ≥30, or BMI 27–29.9 with weight-related conditions
- Both are prescription-only and require clinical assessment
- Mounjaro starts at 2.5 mg weekly; Wegovy starts at 0.25 mg weekly
- Mounjaro escalates to maximum 15 mg; Wegovy to maximum 2.4 mg
- Both are used alongside reduced-calorie diet and increased physical activity
Which medication a prescriber recommends depends on your individual health profile, previous medication responses, and local ICB formulary decisions — not patient choice alone.
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.
How NHS Mounjaro Access Works And What To Expect
NHS access to Mounjaro requires referral from your GP to a specialist tier 3 weight management service. You'll attend an assessment appointment where a specialist team (dietitian, nurse, doctor) will evaluate your weight, health conditions, BMI, and suitability for medication. If approved, you'll receive injections through NHS clinics and regular follow-up appointments. Waiting times vary significantly by region — some areas have waits of several months to over a year. Use our free BMI calculator above to check your starting point, then discuss referral options with your GP.
- 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 get Mounjaro on the NHS?
You need a BMI of 30 or above, or 27–29.9 if you have weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply (27.5 or above). Your GP will assess whether you meet your local ICB criteria.
Is Mounjaro available on the NHS without a referral?
No. NHS Mounjaro requires a GP referral to a specialist tier 3 weight management service. Standard GPs cannot prescribe Mounjaro on the NHS — it must be initiated and managed through specialist services. Private prescription is available through online clinics following clinical assessment, but this is not NHS-funded.
How does Mounjaro compare to Wegovy on the NHS?
Both have similar eligibility criteria (BMI ≥30, or 27–29.9 with health conditions). Mounjaro uses dual GIP+GLP-1 mechanism and achieved around 20.9% average weight loss in trials, while Wegovy uses GLP-1 only with approximately 14.9% average loss. Both require prescription, clinical assessment, and lifestyle changes. Your prescriber will recommend the most suitable option for your health profile.
What health conditions qualify me for NHS Mounjaro?
Weight-related health conditions that may qualify you include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats (dyslipidaemia), obstructive sleep apnoea, and history of heart attack or stroke. You also qualify if your BMI is 30 or above regardless of other conditions. Your specialist will assess your specific situation.
How long does it take to get Mounjaro prescribed on the NHS?
Waiting times vary significantly by region and local ICB capacity. Some areas have waits of several months, while others may exceed one year. You can contact your local specialist weight management service to ask about current waiting times after your GP referral. Private prescription typically has shorter waiting times but involves costs.
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.