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
Free tracker included with every download this week
How Much Does Mounjaro Cost in the UK?
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection, but costs vary significantly between NHS and private routes in the UK. Understanding your options—including NHS specialist services, private online prescribing, and dose costs—can help you find the most affordable access route for your situation. MyWeightCheck provides this information to help you make an informed decision about weight management 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.
Private Prescription Costs for Mounjaro in the UK
Private online prescription is currently the most accessible route for UK adults seeking Mounjaro. Costs typically range from £129 to £320 per month, depending on your dose level. A standard KwikPen contains four weekly injections (one month's supply).
- Starting doses (2.5 mg–5 mg): usually £129–£169 per month
- Mid-range doses (7.5 mg–10 mg): typically £189–£249 per month
- Higher doses (12.5 mg–15 mg): generally £269–£320 per month
These prices are indicative across GPhC-registered pharmacies. You will need a prescription from a UK-licensed prescriber following an online clinical assessment. This assessment usually costs £30–£50 and is separate from the medication cost. Many private providers bundle both the assessment and first prescription together.
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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 Access vs Private Prescription Routes
The NHS has approved tirzepatide (Mounjaro) for use within specialist weight management services (tier 3/4), meaning it can be prescribed free if you meet eligibility criteria and are referred through your GP. However, NHS availability varies significantly by region and waiting times can be very long—some areas report waits of 6–18 months. Private prescription offers faster access without NHS referral but requires payment. Use our free BMI calculator to check your eligibility, then discuss your options with your GP or explore private online prescribing for quicker access.
- 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 cheapest way to get Mounjaro in the UK?
The cheapest route depends on your circumstances. NHS prescription is free if you meet eligibility (BMI ≥30, or ≥27 with weight-related health conditions) and gain referral to specialist services—but waiting lists are long. Private prescription costs £129–£320/month depending on dose. For fastest access to lower doses, private is typically cheaper than waiting months for NHS assessment.
Do I need a prescription for Mounjaro in the UK?
Yes, Mounjaro is prescription-only. You cannot buy it without a valid UK prescription from a licensed prescriber. NHS prescriptions are free once issued; private prescriptions require payment to both the prescriber (assessment fee) and pharmacy (medication cost). Always check the prescriber is registered with the GMC and the pharmacy is GPhC-registered.
Can I get Mounjaro free on the NHS?
If you meet NICE eligibility criteria and are referred to an NHS specialist weight management service, Mounjaro is free. However, not all regions have equal access, and waiting lists are substantial in many areas. Contact your GP about referral to tier 3 services in your area and ask about expected waiting times before deciding between NHS and private routes.
How much does a Mounjaro KwikPen cost privately?
A KwikPen (four weekly doses) costs between £129–£320 depending on your dose strength. Starting doses are cheapest; maximum doses (15 mg) are most expensive. Prices are similar across UK GPhC-registered pharmacies, though you may find minor variations. Always factor in the prescriber's assessment fee (£30–£50) when calculating total first-month cost.
Is Mounjaro cheaper than Wegovy in the UK?
Pricing is similar between Mounjaro and Wegovy across GPhC-registered pharmacies (roughly £129–£320/month depending on dose). However, Mounjaro's dual GIP/GLP-1 mechanism differs from Wegovy's single GLP-1 action, and individual responses vary. Compare both via private prescribers, then discuss with your GP which might suit your health profile better. Our weight loss calculator can help estimate potential outcomes. ---END---
Ready to take control of your weight loss journey?
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