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 in the UK?
Mounjaro (tirzepatide) is available in the UK through both NHS specialist weight management services and private prescription routes, with costs varying significantly depending on which route you choose. Understanding the price differences and eligibility criteria can help you make an informed decision about accessing this prescription weight loss injection. This guide covers current UK pricing, access routes, and what to expect at each dose level.
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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.
Private Prescription Costs for Mounjaro in the UK
Private prescription costs for Mounjaro vary depending on the dose and prescribing provider. Through private online prescribing services, a single KwikPen (containing four weekly doses) typically costs between £150 and £280, depending on the dose strength and provider. The starting dose (2.5 mg) is usually at the lower end of this range, while the maximum dose (15 mg) costs more.
- Dose 2.5 mg: typically £150–£170 per KwikPen
- Dose 5 mg: typically £170–£190 per KwikPen
- Dose 10 mg: typically £200–£240 per KwikPen
- Dose 15 mg: typically £240–£280 per KwikPen
Each KwikPen provides a four-week supply of once-weekly injections. Private prescriptions require a clinical assessment from a UK-licensed prescriber. Costs may vary between providers, so comparing options is worthwhile. Many people using private prescriptions stay on a dose for several weeks before increasing, meaning the actual monthly cost depends on your titration schedule.
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 Access: Routes and Eligibility
NHS access to Mounjaro is free but only through tier 3 specialist weight management services following a GP referral. Availability varies significantly across regions, and waiting lists can be substantial—sometimes lasting 12 months or more depending on your local Integrated Care Board (ICB). NICE has approved tirzepatide for NHS use, but capacity constraints mean many patients do not have timely access.
Private access is available without an NHS referral through online consultations with UK-licensed prescribers. You'll complete a health questionnaire, have a virtual assessment, and receive a prescription if deemed clinically appropriate. This route offers faster access and flexibility in dose selection, though you pay the full prescription cost. Both routes require a prescription—Mounjaro is not available to buy over-the-counter.
When considering cost, factor in that prescription weight loss medications work alongside dietary changes and increased physical activity—not instead of them. Our free GLP-1 weight loss calculator can help you understand potential outcomes at different doses, while our BMI calculator helps determine your eligibility based on current guidelines. If you're considering private access, always verify that the prescriber is UK-licensed and registered with the MHRA or General Pharmaceutical Council to ensure safe, legitimate treatment.
- 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 on the NHS for free?
Yes, Mounjaro is available on the NHS through specialist tier 3 weight management services following a GP referral. However, NHS availability varies by region and waiting times can be lengthy. NICE approved tirzepatide in 2024, but capacity is limited. Access depends on your local ICB and meeting eligibility criteria.
How much does a Mounjaro KwikPen cost privately in the UK?
A single KwikPen (four weekly doses) costs approximately £150–£280 privately, depending on dose strength. The starting 2.5 mg dose is around £150–£170, while the maximum 15 mg dose costs £240–£280. Costs may vary slightly between prescribing providers.
What is included in the private Mounjaro prescription cost?
The private prescription cost covers the medication itself (the KwikPen) and the clinical assessment. It typically does not include follow-up consultations, which may incur additional fees. Always check what is included with your chosen provider before proceeding.
How do I access Mounjaro privately in the UK?
Private access is available through online consultations with UK-licensed prescribers. You complete a health questionnaire, have a virtual assessment, and receive a prescription if appropriate. The prescription is then dispensed by a GPhC-registered pharmacy. Always verify the prescriber is legitimately registered.
How long does a KwikPen last, and what is the actual monthly cost?
Each KwikPen contains four weekly doses and lasts one month. However, you'll typically stay on each dose for 4+ weeks during titration, meaning your actual monthly spend may remain steady for several weeks before increasing to the next dose level during your treatment journey.
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.