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 15mg Cost in the UK?
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private online prescribing, but costs vary significantly depending on which route you choose. The maximum dose—15mg—is typically reached after several weeks of dose titration starting from 2.5mg. Understanding the cost difference between NHS and private access, along with what affects pricing, helps you make an informed decision about weight management treatment in the UK.
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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 Mounjaro Cost and Pricing Factors
Private prescription costs for Mounjaro 15mg typically range from £180 to £320 per month depending on the provider, dose level, and whether you're on a subscription or pay-per-dose basis. A single KwikPen device contains 4 weeks' worth of injections (one per week). Since Mounjaro requires dose titration—starting at 2.5mg and escalating every 4 weeks—your initial costs will be lower than the maximum-dose price. At 2.5mg, costs may begin around £100–£150 per month, rising progressively as you increase dose.
- Subscription plans often offer discounts compared to one-off purchases
- Private providers vary in pricing structure—some charge per dose level, others per month
- Online consultation fees (typically £15–£50) are usually charged separately or included in the first order
- No prescription charge applies beyond the medication cost itself
When comparing prices for Mounjaro 15mg, remember you're paying for the full KwikPen (4 weeks' supply), not individual doses. Costs remain consistent once you've stabilised at your maintenance dose, making longer-term budgeting more predictable than initial titration.
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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.
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: Availability and Timeline
NHS access to Mounjaro is available through specialist tier 3 and tier 4 weight management services, but availability varies significantly by region and involves referral pathways that can result in waiting lists of many months. Private online prescribing offers faster access—typically within 1–7 days of completing an online clinical assessment—but at a cost. Both routes require a clinical assessment confirming you meet eligibility criteria: a BMI of 30 or above, or 27–29.9 with weight-related health conditions including type 2 diabetes, prediabetes, hypertension, or cardiovascular disease.
Use our GLP-1 weight loss calculator to estimate potential outcomes with tirzepatide, and our BMI calculator to confirm your eligibility status before pursuing either route.
- 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 in the UK?
Yes, Mounjaro (tirzepatide) is NICE-approved for NHS use in specialist weight management services (tier 3/4). However, access depends on your local Integrated Care Board (ICB) commissioning, referral from your GP, and availability. Waiting times vary from weeks to over a year in some areas.
How much does a Mounjaro 15mg KwikPen cost privately?
Private Mounjaro 15mg costs typically £200–£320 per month depending on the provider. This price is for a full KwikPen (4 weeks). Lower doses cost less during titration. Prices may vary; always confirm the exact cost before purchasing.
Why does Mounjaro cost more at higher doses?
Mounjaro pricing is per KwikPen per dose level—5mg, 10mg, 15mg pens are separate products. Providers set prices per dose, and 15mg (the maximum) is the highest-priced tier. This reflects manufacturing and distribution costs, not just the active ingredient amount.
Can I get Mounjaro cheaper through NHS than privately?
If you access Mounjaro through the NHS, there is no direct cost (covered by the NHS), making it free at point of use. However, NHS access involves waiting lists and geographic variation. Private access costs £180–£320/month but offers faster availability without referral delays.
What's included in Mounjaro private prescription cost?
The private cost covers the KwikPen device, four weekly doses, and the prescription itself. Online consultation fees (£15–£50) are separate at some providers, included in others. No NHS prescription charge applies on top of the medication cost.
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.