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 Much Does Mounjaro Cost The NHS?
Mounjaro (tirzepatide) is available through the NHS, but costs and access vary significantly by region. Unlike private prescriptions, NHS patients don't pay per dose — weight management treatment is provided as part of specialist tier 3 and tier 4 services. NICE has approved tirzepatide for NHS use, but availability depends on your local Integrated Care Board (ICB) and capacity within specialist weight management services. This guide explains NHS costs, how they compare to Wegovy, and what affects your access.
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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 Access and NICE Approval for Mounjaro
NHS funding for Mounjaro: Patients receive tirzepatide through NHS specialist weight management services at no per-dose cost — you pay only standard NHS prescription charges (currently £9.90 per item in England, or free if eligible). However, availability is not uniform across the UK. NICE approved tirzepatide in 2024 for use within NHS weight management pathways, but local ICBs decide budget allocation and waiting lists.
- Tier 3 specialist services (community-based multidisciplinary teams) typically prescribe Mounjaro following referral from your GP
- Waiting times range from weeks to many months depending on your region
- Dose titration follows the standard protocol: starting at 2.5 mg, increasing every 4 weeks to a maximum of 15 mg
- NHS supply includes the Kwikpen injectors and clinical monitoring
Unlike private prescriptions, you don't pay per dose — your only cost is the prescription charge (if applicable). However, accessing NHS Mounjaro requires referral and assessment; not all patients will be approved.
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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.
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Mounjaro vs Wegovy: NHS Costs and Eligibility Comparison
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are approved by NICE for NHS use, but they work differently and have different evidence bases. Cost to the patient: Both cost the same on the NHS (prescription charge only). Clinical differences: Mounjaro is a dual GIP+GLP-1 receptor agonist; Wegovy is a GLP-1-only agonist. SURMOUNT trial data showed Mounjaro participants lost approximately 15–21% body weight; STEP trial data showed Wegovy participants lost approximately 15% body weight on average — though individual results vary significantly.
- Eligibility criteria are identical for both: BMI ≥30 or BMI 27–29.9 with weight-related health conditions
- Which medication your prescriber offers may depend on local ICB formulary decisions and current stock availability
- Both require the same assessment process and ongoing clinical monitoring
Your GP or specialist prescriber will assess which is most suitable for you individually.
- 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.
Do I have to pay for Mounjaro on the NHS?
NHS patients pay only the standard prescription charge (£9.90 in England, or free if exempt) — not per dose. Private patients pay approximately £129–£320 per month depending on dose. However, not all patients qualify for NHS access; you must be referred to a specialist tier 3 service and meet eligibility criteria.
How long is the NHS waiting list for Mounjaro?
Waiting times vary significantly by region. Some areas have waiting lists of several months to over a year. Contact your local ICB or ask your GP for current waiting times in your area. Private prescribing is typically faster but involves full private costs.
Is Mounjaro cheaper than Wegovy on the NHS?
No — both cost the same on the NHS (prescription charge only). The difference is in mechanism: Mounjaro is dual GIP+GLP-1; Wegovy is GLP-1 only. Clinical trial data shows both support significant weight loss on average. Your prescriber will recommend based on individual suitability and local availability.
How do I access Mounjaro through the NHS?
Ask your GP for a referral to your local specialist weight management service (tier 3). Your GP will assess whether you meet eligibility criteria (BMI ≥30 or BMI 27–29.9 with weight-related conditions). You'll then be assessed by the specialist team before prescription. This process typically takes weeks to months depending on waiting lists.
What's the difference between Mounjaro and Wegovy doses?
Mounjaro starts at 2.5 mg and increases to a maximum of 15 mg weekly. Wegovy starts at 0.25 mg and increases to a maximum of 2.4 mg weekly. They use different dosing schedules because tirzepatide is more potent. Both are titrated gradually to reduce side effects — dose adjustment takes approximately 4–5 months on either medication.
Ready to take control of your weight loss journey?
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