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
What Does Mounjaro Cost in the UK?
Mounjaro (tirzepatide) costs vary significantly in the UK depending on whether you access it through the NHS or privately. Private prescription costs typically range from £129 to £320 per month depending on your dose, with the starting 2.5mg dose at the lower end and the maximum 15mg dose at the higher end. NHS access is free at point of use but requires referral to a specialist weight management service, and availability varies greatly by region. Understanding your options helps you make an informed decision about accessing this prescription-only weight management injection.
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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 Mounjaro Costs and Access Routes
Private prescription costs in the UK for Mounjaro range from approximately £129 to £320 per month, depending on your dose and the provider. Each prescription includes one pre-filled KwikPen with four weekly doses (one month supply). The 2.5mg starting dose is typically the cheapest option at around £129–£180, whilst higher doses (10mg, 15mg) cost £250–£320 monthly. To access Mounjaro privately, you'll need an online clinical assessment with a UK-licensed prescriber, usually costing £20–£40. Once approved, the prescription is dispensed by a GPhC-registered pharmacy. Some providers offer dose escalation packages that may work out cheaper per month than pay-as-you-go. Remember that tirzepatide requires a minimum of 4 weeks on each dose before increasing, so you cannot rush through to a higher maintenance dose.
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: How to Get the Best Value
The NHS route is free but involves a significant wait: you'll need GP referral to your local tier 3 specialist weight management service, with waiting lists ranging from 6 months to 2+ years depending on your area. NHS access requires a BMI of 30+ (or 27+ with weight-related health conditions like type 2 diabetes), and availability is limited by regional capacity. Private access is faster—usually within days—and doesn't require NHS referral, but you pay directly. For cost-conscious patients, private is often better value if you can pay upfront, as you avoid months of waiting. Use our free GLP-1 weight loss calculator to estimate potential results at different doses, which helps justify the investment. Check eligibility with our BMI calculator first to understand your starting position.
- 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.
Why is Mounjaro more expensive at higher doses?
Higher doses require larger amounts of the active ingredient tirzepatide. A 15mg dose contains six times more medication than a 2.5mg dose, so manufacturing and supply costs are proportionally higher. Pharmacy markups also increase with dose strength. However, staying on a lower effective dose may be cheaper overall than paying for a higher dose you don't need.
Can I get Mounjaro on the NHS for weight loss?
Yes, but only through specialist tier 3 weight management services, not from your GP directly. You need a BMI of 30+ or 27+ with weight-related conditions. NICE has approved tirzepatide for NHS use, but regional availability is very limited and waiting lists are often 12–24 months or longer. Ask your GP about referral options in your area.
What does the online consultation cost if I go private?
Most UK online prescribing services charge £20–£40 for the initial clinical assessment. This is separate from the medication cost. Some providers include the consultation fee in their monthly package, whilst others charge separately. Always confirm the total cost upfront before proceeding.
How much cheaper is it to start on 2.5mg instead of jumping to higher doses?
Starting on 2.5mg typically costs £30–£60 less per month than a 10mg dose. However, you must follow the titration schedule (staying on each dose for 4 weeks minimum). You cannot skip doses to save money—rushing the dose escalation defeats the purpose and increases nausea and side effects.
Does Mounjaro KwikPen cost less than getting it from different pharmacies?
The medication and KwikPen device cost the same regardless of pharmacy—pricing is set by the manufacturer. Different providers may have slightly different consultation fees or package deals, so compare total costs (consultation + medication) rather than just the injection price. Some offer cheaper ongoing doses after the first month.
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.