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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Best Value Mounjaro in the UK — Cost & Access
Getting Mounjaro (tirzepatide) at the best value in the UK depends on whether you access it through the NHS or private prescription routes. Mounjaro is a prescription-only GLP-1 weight loss injection licensed for adults with a BMI of 30 or above, or 27 or above with weight-related health conditions. This guide explains the cost differences, how to access Mounjaro affordably, and what to expect from each pathway. Use our free GLP-1 weight loss calculator to explore potential outcomes, and our BMI calculator to check your current health status.
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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.
Understanding Mounjaro Costs in the UK
Mounjaro pricing in the UK varies significantly depending on your access route. Private prescription costs typically range from £129 to £320 per month, depending on your dose and the online prescribing provider. The starting dose (2.5 mg KwikPen) is usually at the lower end of this range, with costs increasing as you titrate to higher doses. Each KwikPen contains 4 weekly injections, lasting one month.
NHS access through specialist tier 3 weight management services is free at point of care, but availability varies dramatically by region and ICB (Integrated Care Board). Many areas have significant waiting lists—sometimes 6 months to 2 years—and eligibility criteria can be strict. NHS prescribing focuses on tirzepatide (the generic/chemical name) rather than the branded Mounjaro KwikPen specifically.
- Private: £129–£320/month depending on dose
- NHS: Free once approved, but regional variation and waiting lists
- Mounjaro KwikPen: 4 injections per pen (one month supply)
- Dose titration: typically increases every 4 weeks, so costs may rise as you progress
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 vs Private Routes — Which Offers Best Value?
NHS route offers zero cost once accessed, making it the best financial value—but requires a GP referral to tier 3 services and can involve lengthy waiting lists. Private route costs more monthly but offers immediate access without NHS waiting times. For best value privately, compare providers' pricing at different doses: a 5 mg dose costs less than 10 mg or 15 mg titration pens. Some private providers offer multi-month subscription discounts. Consider your timeline: if you can wait for NHS access in your region, the cost saving is substantial. If you need to start immediately, private prescription weight loss offers faster access. Always ensure any prescriber is UK-licensed and the pharmacy is GPhC-registered. Our weight loss calculator can help you project outcomes at different doses to inform your decision.
- 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 is the typical cost of Mounjaro in the UK on private prescription?
Private Mounjaro costs range from approximately £129 to £320 per month, depending on your dose. Starting doses (2.5 mg) are usually cheaper; maximum doses (15 mg) cost more. Costs increase as you titrate upward. Some providers offer discounts for multi-month commitments, making long-term private access more affordable.
Can I get Mounjaro free on the NHS in the UK?
Yes, Mounjaro (tirzepatide) is available free on the NHS through specialist tier 3 weight management services. However, access requires a GP referral, meets strict eligibility criteria, and involves waiting lists that can extend 6 months to 2 years in some areas. Regional availability varies significantly.
How much does a Mounjaro KwikPen cost, and how long does it last?
A single Mounjaro KwikPen costs between £129 and £320 privately, depending on the dose. Each pen contains 4 weekly injections, lasting one month. As you titrate through doses (2.5 mg → 5 mg → 10 mg, etc.), each subsequent pen may cost more, so total monthly costs can increase during your treatment journey.
Is private Mounjaro prescription cheaper than Wegovy in the UK?
Pricing is often comparable between Mounjaro and Wegovy (semaglutide) in the UK private market, typically £129–£320/month depending on dose. Mounjaro may offer slightly faster weight loss in clinical trials, but individual results vary. Compare providers' pricing for both medications to find the best value for your circumstances.
What should I check to ensure I'm getting best value Mounjaro online in the UK?
Verify the prescriber is UK-licensed and the pharmacy is GPhC-registered. Compare pricing across providers at your target dose. Check whether they offer subscription discounts for 3–6 month commitments. Ask about ongoing support and dose adjustments. Ensure the consultation assesses your medical history properly—cheapest isn't always safest.
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.