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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Does The NHS Prescribe Mounjaro In The UK?
Yes, the NHS does prescribe Mounjaro (tirzepatide), but access is limited and varies significantly by region. Mounjaro is available through NHS specialist tier 3 and tier 4 weight management services, not standard GP prescription. You'll need referral from your GP to a specialist weight management clinic, and availability depends on your local integrated care board (ICB). Many people find private prescription routes faster and more accessible. This guide explains both NHS and private options for accessing Mounjaro in the UK, eligibility criteria, and what to expect.
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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 — Specialist Services Route
NHS Mounjaro is prescribed through specialist tier 3 and tier 4 weight management services, not by your standard GP. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for use within these specialist services for eligible adults.
- Referral required: Your GP must refer you to your local NHS specialist weight management service
- Assessment: The specialist team will assess your BMI, weight-related health conditions, and suitability for Mounjaro
- Eligibility: Generally BMI ≥30, or BMI 27–29.9 with comorbidities such as type 2 diabetes, high blood pressure, or sleep apnoea
- Waiting lists: NHS specialist services have significant waiting times in most areas — often several months to over a year
- Regional variation: Availability differs greatly between ICBs; some areas have better access than others
- Monitoring: Once prescribed, you receive regular clinical monitoring and support through the NHS service
NHS access means the medication cost is covered, but the wait and limited clinic availability make this route inaccessible for many people seeking weight management support now.
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 Mounjaro — Faster Access & Cost Considerations
Private prescription is the faster route for most people in the UK. You can obtain a Mounjaro prescription through a GPhC-registered online pharmacy following a brief clinical assessment with a UK-licensed prescriber — no NHS referral needed.
- Private prescription cost: Approximately £129–£320 per month depending on your dose and provider, as you're paying for the medication out of pocket
- Assessment process: Completed online through questionnaire and sometimes a video consultation
- Speed: From assessment to receiving your first KwikPen typically takes 2–7 days
- Ongoing support: Varies by provider; some offer follow-up consultations for dose monitoring
- No waiting lists: Unlike NHS services, private routes avoid lengthy delays
Private prescribing allows faster access to treatment but requires you to cover the full medication cost. You can compare Mounjaro vs Wegovy pricing and effectiveness through private providers to find the best option for your circumstances.
- 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 my GP prescribe Mounjaro directly on the NHS?
No, your GP cannot prescribe Mounjaro under standard NHS prescribing. It is only available through specialist tier 3 and tier 4 weight management services. Your GP can refer you to these services, but prescription is managed by the specialist team. Private prescription from online providers is the main alternative.
How long is the NHS waiting list for Mounjaro?
NHS waiting times vary significantly by region (ICB). Many areas have waiting lists of 6–12 months or longer. Some regions with better-resourced services may be faster. Contact your local NHS weight management service for specific waiting times in your area.
What does Mounjaro cost on private prescription in the UK?
Private Mounjaro typically costs £129–£320 per month depending on your dose (starting 2.5 mg to maximum 15 mg). Costs vary between providers. You pay the full amount privately — it is not covered by the NHS when prescribed privately.
What is the difference between NHS and private Mounjaro?
The medication is identical. The main differences are: NHS access requires referral and specialist assessment with longer waiting times; private access is faster and doesn't require NHS referral. NHS covers the cost; private prescription is out-of-pocket. Both require clinical assessment and suitability.
Is Mounjaro available as a KwikPen on both NHS and private routes?
Yes, Mounjaro is supplied as a pre-filled KwikPen on both NHS and private prescriptions. The KwikPen device and administration method are the same regardless of how you access the medication. Your prescriber will provide instructions on injection technique.
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.