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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Taking Mounjaro in the UK — How to Access and What It Costs
If you're considering taking Mounjaro for weight management in the UK, you need to understand your access options and what to expect. Mounjaro (tirzepatide) is a prescription-only injectable medication licensed for weight management in UK adults. Access is available through both NHS specialist services and private online prescribing routes, each with different costs, timescales, and eligibility criteria. This guide explains how to get started, what you'll pay, and the clinical assessment process you'll need to complete before beginning 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 Mounjaro Access in the UK — Cost and Process
Private prescription costs for Mounjaro in the UK typically range from £150–£300 per month, depending on the dose you're prescribed and the provider you choose. Starting doses (2.5 mg) are generally at the lower end of this range, while higher maintenance doses (10–15 mg) cost more. Each KwikPen contains four weekly injections, so costs work out at roughly £40–£75 per week depending on your dose. Private access involves an online consultation with a UK-licensed prescriber, who will assess your eligibility based on your BMI, health history, and any weight-related conditions. Use our GLP-1 weight loss calculator to understand projected weight loss at different doses — this information is helpful during your consultation. If approved, your prescription is dispensed by a registered pharmacy and delivered to your home. The entire process typically takes 3–7 days from initial consultation to receiving your first pen.
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 Routes — What's the Difference?
NHS access to Mounjaro is through tier 3 specialist weight management services, following a referral from your GP. NICE has approved tirzepatide for use within the NHS, but availability is extremely variable by region — some areas have waiting lists of many months or years, while others may have limited services. There is no cost to you on the NHS, but the wait can be significant. Private online prescribing bypasses NHS waiting lists entirely; you can start treatment within days of approval. However, you pay the full cost of the medication yourself. Our BMI calculator can help you determine your eligibility before contacting a provider — you'll need a BMI of 30 or above, or 27–29.9 with qualifying health conditions. Ask your GP about NHS tier 3 services in your area if you prefer NHS-funded treatment, even if you're also exploring private options.
- 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.
How much does Mounjaro cost on the NHS in the UK?
Mounjaro is available on the NHS through specialist tier 3 weight management services and costs nothing to you as a patient. However, NHS availability varies significantly by region, and waiting times can be very long in many areas. Contact your GP to ask about specialist weight management services in your local area.
Can I get Mounjaro (tirzepatide) prescribed privately in the UK?
Yes. Private UK-licensed prescribers offer online consultations for Mounjaro. You'll complete a clinical assessment, and if approved, your prescription is dispensed by a registered pharmacy. Costs typically range from £150–£300 per month depending on your dose, with no NHS waiting lists involved.
What do I need to qualify for Mounjaro in the UK?
You must have a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related health condition (such as high blood pressure, type 2 diabetes, or heart disease). You'll also need a clinical assessment confirming you're medically suitable. Lower BMI thresholds apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage.
How long does it take to get Mounjaro through a private UK prescription?
Private online consultations typically take 24–48 hours for a decision. If approved, your KwikPen is usually dispatched within 2–3 working days. You could have your first dose within a week of initial consultation, compared to months or years on some NHS waiting lists.
Will I need dose titration (starting low and increasing) with Mounjaro?
Yes. Treatment typically starts at 2.5 mg weekly for 4 weeks, then increases by 2.5 mg every 4 weeks until you reach your target maintenance dose (usually 10–15 mg). Your prescriber will guide you through this process and monitor your progress using your feedback and, where relevant, weight checks.
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.