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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Getting Mounjaro in the UK — Cost and Access Routes
Mounjaro (tirzepatide) is available in the UK through two main routes: NHS specialist weight management services and private prescription. Costs, eligibility, and waiting times vary significantly depending on which route you choose. This guide covers what you need to know about accessing Mounjaro in the UK, from NHS criteria to private prescription costs, so you can understand your options and what to expect.
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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.
Mounjaro Cost — Private Prescription Pricing by Dose
Private Mounjaro prescriptions in the UK typically cost between £129 and £320 per month, depending on the dose and provider. Here's what you can expect:
- Starting doses (2.5–5 mg): approximately £129–£160 per month
- Mid-range doses (7.5–10 mg): approximately £180–£240 per month
- Higher doses (12.5–15 mg): approximately £240–£320 per month
Each prescription covers a 4-week supply (one KwikPen with 4 pre-filled doses). Costs may vary between GPhC-registered pharmacies. Many providers offer subscription discounts for recurring monthly orders. Private prescriptions require an online clinical assessment with a UK-licensed prescriber, typically costing £20–£50.
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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 vs Private Access — Routes and Timeline
NHS route: Free on prescription through tier 3 specialist weight management services, but access requires GP referral and assessment. NICE has approved tirzepatide for NHS use, but availability varies by region (integrated care board). Waiting times can be several months to over a year in many areas.
Private route: Faster access — typically 2–5 days from online assessment to first prescription. No GP referral needed. Requires private payment monthly. Both routes involve dose titration starting at 2.5 mg, increasing weekly doses over 16–20 weeks until reaching your target maintenance dose.
- 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 free on NHS prescription if you're eligible and can access it through a tier 3 specialist weight management service. However, NHS availability is limited and varies by region. You'll need a GP referral and may face significant waiting lists. Check with your local integrated care board about availability.
What's the difference between NHS and private Mounjaro access?
NHS Mounjaro is free but involves GP referral, specialist assessment, and regional waiting lists (sometimes months to years). Private Mounjaro costs £129–£320/month depending on dose, requires only an online clinical assessment, and is typically available within days. Both follow the same medical protocols and dose titration.
Do I need a GP referral to get private Mounjaro?
No. For private Mounjaro, you complete an online consultation with a UK-licensed prescriber directly — no GP referral needed. The prescriber assesses your eligibility based on your BMI, health history, and current medications. If approved, your prescription is sent to a GPhC-registered pharmacy for delivery.
How does Mounjaro dose titration work in the UK?
You start on 2.5 mg weekly, then increase by increments (5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg) every 4 weeks until reaching your target dose. Your prescriber guides this process. Each dose increase is a separate KwikPen prescription, which is why monthly costs rise as you titrate upward.
Can I switch from Wegovy to Mounjaro in the UK?
Yes, but only under prescriber guidance. Mounjaro is a dual GIP/GLP-1 agonist while Wegovy is GLP-1 only, so they work differently. An approximate equivalence exists (Mounjaro 10 mg ≈ Wegovy 1.7 mg), but any switch must be managed by your prescriber to ensure safe transition and appropriate dose adjustment.
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.