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 Jabs in the UK: NHS Access and Prescribing
Mounjaro jabs (tirzepatide) are prescription-only weight loss injections now available through the NHS in the UK. These weekly injections work as a GLP-1 and GIP receptor agonist to help reduce appetite and support weight management alongside diet and exercise. Access is primarily through specialist tier 3 weight management services rather than standard GP prescribing. This guide explains NHS eligibility, how the service works, waiting times, and what to expect from Mounjaro treatment in a UK health context.
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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.
NHS Eligibility and Tier 3 Weight Management Services
NICE approved tirzepatide (Mounjaro) for use within NHS specialist weight management services in 2023, making it available on prescription to eligible adults. However, access is not through your standard GP appointment — you must be referred to a tier 3 or tier 4 specialist weight management service.
- Eligibility criteria: Adults with a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, prediabetes, high blood pressure, sleep apnoea, or cardiovascular disease)
- South Asian, Chinese, Black African, or Black Caribbean adults: Lower thresholds may apply — eligibility can start at BMI 27.5 or above due to higher health risks at lower BMI
- Age requirement: Must be 18 or over
- Referral: Your GP can refer you, but availability depends on your local Integrated Care Board (ICB)
Tier 3 services provide multidisciplinary support including dietary advice, psychological support, and regular clinical monitoring alongside the medication. Check your local NHS commissioning guidance for specific eligibility and referral pathways.
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: Waiting Times and Private Alternatives
NHS Mounjaro prescribing varies significantly across the UK. Many areas have substantial waiting lists for tier 3 weight management services — in some regions, waiting times exceed 18 months. MHRA approval of tirzepatide has increased demand, and capacity constraints mean not all eligible patients can access the medication immediately.
Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Private costs typically range from £150–£250 per month depending on dose. This route allows faster access without NHS waiting lists but requires self-funding. Use our GLP-1 weight loss calculator to estimate potential outcomes at different doses, and our BMI calculator to confirm your current category against NHS eligibility thresholds.
- 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 the UK?
Yes. NICE approved tirzepatide (Mounjaro) for NHS use in 2023. Access is through specialist tier 3 weight management services via GP referral, not standard GP prescribing. Availability depends on your local Integrated Care Board, and waiting lists can be long. Your GP can refer you if you meet eligibility criteria.
What are the NHS eligibility criteria for Mounjaro jabs?
You must have a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. South Asian, Chinese, Black African, and Black Caribbean adults may be eligible at BMI 27.5 or above. You must be 18 or over. Tier 3 services assess full medical history during consultation.
How long are NHS waiting lists for Mounjaro?
Waiting times vary by region. Many areas have waiting lists of 6–18 months for tier 3 weight management services. Some regions have shorter waits; others have longer delays. Contact your local NHS commissioning team or ask your GP to check current waiting times in your area, as capacity is often limited.
What's the difference between NHS and private Mounjaro access in the UK?
NHS access is free but involves waiting lists and tier 3 referral. Private access is available immediately through online prescribers but costs £150–£250 monthly. Both require clinical assessment. Private is faster; NHS is no-cost but demand is high. Some people access privately while waiting for NHS.
Does Mounjaro cost anything on the NHS?
No. Once you access Mounjaro through an NHS tier 3 service, the medication is provided free as a prescription item. There is no patient cost. Private access costs approximately £150–£250 per month depending on dose and provider. NHS waiting times mean some patients choose private access for faster treatment. ```
Ready to take control of your weight loss journey?
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