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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How Can I Get Mounjaro For Free in the UK?
Getting Mounjaro (tirzepatide) for free in the UK is possible through the NHS, but access is limited and varies significantly by region. The NHS has approved tirzepatide through NICE for specialist weight management services, though availability depends on your local integrated care board (ICB) and whether you meet strict eligibility criteria. Most UK adults currently access Mounjaro privately through GPhC-registered online prescribing services. This guide explains NHS access routes, eligibility requirements, and what free options realistically exist for UK patients seeking this weight loss treatment.
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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 to Mounjaro in the UK
The NHS route is theoretically free, but access is severely restricted. Tirzepatide (Mounjaro's generic name) has been approved by NICE for use within specialist tier 3 and tier 4 weight management services in England. However, availability varies dramatically across the country — some ICBs have funding and active programmes, whilst others have no access or very long waiting lists stretching months or years.
To access Mounjaro on the NHS, you typically need to:
- Be referred to a specialist weight management service by your GP (not available through standard GP prescription)
- Have a BMI of 30 or above, or 27–29.9 with weight-related health conditions
- Have tried lifestyle changes without sufficient weight loss
- Pass a clinical assessment with the specialist service
- Have no contraindications to GLP-1 or dual GIP/GLP-1 agonists
Even when you meet these criteria, NHS funding decisions depend on your local commissioning arrangements. Some regions prioritise Mounjaro; others offer Wegovy or Saxenda first. Ask your GP whether your local ICB funds tirzepatide and what the current waiting times are.
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.
Private Access and Realistic Alternatives
Most UK adults currently obtain Mounjaro through private prescribing rather than waiting for NHS access. A UK-licensed prescriber completes an online clinical assessment, and if suitable, issues a prescription which is dispensed by a GPhC-registered pharmacy. Costs range from approximately £129–£320 per month depending on dose and provider.
If you cannot access Mounjaro free on the NHS, alternatives include: asking your GP about waiting list timescales; exploring whether your ICB funds other weight loss injections like Wegovy or Saxenda (which have similar mechanisms); or considering private prescribing if financially feasible. Our GLP-1 weight loss calculator can help you estimate potential outcomes with different medications and doses, helping inform discussions with your prescriber.
- 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.
Is Mounjaro available free on the NHS?
Yes, but only through specialist tier 3/4 weight management services in areas with NHS funding. Access is geographically restricted and waiting lists can be very long. Your GP can check whether your local integrated care board (ICB) funds tirzepatide and current waiting times.
What are the NHS eligibility criteria for Mounjaro?
You typically need a BMI of 30 or above (or 27–29.9 with weight-related conditions), failed lifestyle interventions, and referral to specialist services. South Asian, Chinese, Black African, and Black Caribbean adults may have lower BMI thresholds. A specialist assessment is required.
How long are NHS waiting lists for Mounjaro?
Waiting times vary by region from weeks to over a year. Many ICBs have significant backlogs for tier 3 weight management services. Ask your GP to contact your local commissioning service for realistic timescales in your area.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Both are licensed for weight management in the UK. Mounjaro showed slightly higher average weight loss in trials (~21% vs ~15%), though individual results vary considerably.
How much does private Mounjaro cost in the UK?
Private Mounjaro costs approximately £129–£320 monthly depending on dose (starting 2.5mg, up to 15mg weekly). This includes the prescription assessment and dispensing through a GPhC-registered pharmacy — no NHS referral needed.
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.