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?
If you're looking for the cheapest way to access Mounjaro in the UK, you'll need to understand the difference between NHS and private routes. Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection that may help adults with a BMI of 30 or above (or 27–29.9 with weight-related health conditions) lose weight alongside diet and exercise. This guide explains UK costs, eligibility, and how to access this medication affordably.
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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 — What to Expect
Private prescription costs for Mounjaro vary by dose and provider, typically ranging from £129 to £320 per month. Costs are usually highest at the maximum dose (15 mg weekly) and lowest at starter doses (2.5 mg). Your prescriber will start you on 2.5 mg, then increase gradually — so your first month will be cheaper than maintenance doses.
Most costs include:
- Online clinical assessment by a UK-licensed prescriber
- The prescription itself
- Dispensing by a GPhC-registered pharmacy
- Delivery to your home
Some providers offer loyalty discounts or bulk purchase savings if you pay for 3 or 6 months upfront. Always confirm what's included before paying — some quote the medicine price alone, whilst others include the full service.
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 Access vs Private — Key Differences
NHS route: Free once prescribed, but typically only available through specialist tier 3/4 weight management services. You'll need a GP referral and may face waiting lists of several months or longer, depending on your local ICB (Integrated Care Board). NICE approved tirzepatide for NHS use, but regional availability remains limited.
Private route: Faster access — you can start within days of an online assessment without waiting for NHS services. Private costs apply (£129–£320/month depending on dose), but many people prefer the speed and assured access. No NHS referral needed. Use our GLP-1 weight loss calculator to estimate potential results at different doses, which may help you decide if treatment is right for you.
To find the cheapest private option, compare providers offering online Mounjaro prescriptions. Costs vary because different GPhC-registered pharmacies and prescribing services charge different fees. Some specialize in weight loss and may offer better value; others bundle additional support like diet plans or progress tracking. Always check whether the quoted price is per dose, per month, or includes the prescriber's consultation. Ask about starter dose pricing — your first month at 2.5 mg will be cheaper than later doses at 10 mg or 15 mg.
- 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's the average cost of Mounjaro on the NHS in the UK?
Mounjaro is free once prescribed through the NHS, but access is limited to specialist weight management services (tier 3/4) and varies by region. You typically need a GP referral and may face significant waiting lists. NICE approved tirzepatide for NHS use in 2024, but not all areas have implemented it yet.
How much cheaper is Mounjaro at the starting dose compared to the maximum dose?
Starting dose (2.5 mg) typically costs £129–£160 per month, whilst maximum dose (15 mg) costs £280–£320 per month. Your prescriber will increase your dose gradually over weeks, so early costs are lower. Once you reach your maintenance dose, you'll pay the higher amount weekly.
Can I get Mounjaro cheaper by switching between providers?
Yes. Private prescription costs vary between GPhC-registered pharmacies and prescribing services. Comparing 3–5 providers may save £30–£50 per month. Some offer discounts for upfront payment of 3 or 6 months' supply. Always confirm the quoted price includes the prescriber assessment, prescription, and delivery.
Is it cheaper to use a weekly weight loss injection like Mounjaro than Wegovy?
Costs are similar — both Mounjaro and Wegovy typically cost £129–£320/month privately, depending on dose. Mounjaro is a dual GIP/GLP-1 injection, whilst Wegovy is GLP-1 only. Individual results vary, so the "cheapest" option depends on which drug works best for you and your prescriber's recommendation.
How do I know if I'm eligible for Mounjaro on the NHS?
You're potentially eligible if you have a BMI of 30 or above, or BMI of 27–29.9 with a weight-related condition (diabetes, hypertension, sleep apnoea, etc.). Ask your GP about referral to your local tier 3 weight management service. Use our free BMI calculator to check your current BMI, then discuss NHS options with your GP.
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.