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
Who Makes Mounjaro and How to Access It in the UK
Mounjaro (tirzepatide) is manufactured by Eli Lilly and Company, a global pharmaceutical firm. In the UK, Mounjaro is available as a prescription-only medicine for weight management in adults who meet NHS eligibility criteria. You can access Mounjaro through two main routes: NHS specialist weight management services or private online prescription following a clinical assessment. This guide covers who produces Mounjaro, how to access it in the UK, what it costs, and what to expect from the eligibility process. Understanding your options helps you make informed decisions about weight management 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.
How to Access Mounjaro in the UK and What It Costs
Eli Lilly manufactures Mounjaro globally, and it is licensed in the UK by the MHRA (Medicines and Healthcare products Regulatory Agency). The medication comes as a pre-filled KwikPen injection device.
NHS route: Access is through tier 3 specialist weight management services. Your GP can refer you to your local service if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea). NHS waiting lists vary significantly by region—some areas have waits of several months or longer. Once approved, Mounjaro is dispensed free on the NHS.
Private route: Available through UK-licensed prescribers via online consultation. Costs range from approximately £129–£320 per month depending on your dose level. Private providers do not require NHS referral and are often faster to access. A clinical assessment is still required before prescription.
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: Which Route Is Right for You?
The NHS route is free but involves waiting lists and referral through your GP to specialist services. Availability depends on your ICB (Integrated Care Board) region. Some areas have robust tier 3 services; others have limited capacity.
The private route is faster and does not require NHS referral, but costs between £129–£320 monthly depending on your dose (starting at 2.5 mg, rising to a maximum of 15 mg weekly). Private providers assess your eligibility through an online consultation with a UK-licensed prescriber. Try our free GLP-1 weight loss calculator to explore potential outcomes with tirzepatide at different doses. You'll also find our BMI calculator useful for checking whether you meet the BMI eligibility thresholds (30+ or 27+ with health conditions).
- 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 the same as Wegovy?
No. Both are prescription-only weight loss injections available in the UK, but they are different medications made by different manufacturers. Mounjaro (tirzepatide, made by Eli Lilly) is a dual GIP and GLP-1 receptor agonist. Wegovy (semaglutide, made by Novo Nordisk) is a GLP-1 agonist only. Clinical trials show both support weight loss, though individual results vary. Your prescriber will advise which is appropriate for you.
How much does Mounjaro cost on the NHS?
Mounjaro is free on the NHS if prescribed through a specialist tier 3 weight management service. However, access requires referral from your GP and assessment by the service. Waiting times vary by region from weeks to months. Private prescription costs £129–£320 per month depending on your dose level.
Do I need to see my GP first to get Mounjaro?
For the NHS route, yes—your GP can refer you to a specialist weight management service, though access is not assured and depends on local availability and eligibility. For private prescription, you do not need a GP referral. You can book an online consultation directly with a UK-licensed prescriber who will assess your eligibility based on BMI and health conditions.
What dose of Mounjaro will I start on?
Mounjaro uses a dose titration schedule. You start on 2.5 mg once weekly for the first four weeks, then increase to 5 mg in weeks 5–8. Further increases to 7.5 mg, 10 mg, 12.5 mg, or 15 mg may follow depending on your response and tolerability. Your prescriber will guide the pace of dose increases.
How long does the online consultation for private Mounjaro take?
Private online consultations typically take 10–20 minutes. You'll answer health questions, discuss your weight loss goals, and have your BMI and eligibility assessed. If approved, a prescription is issued and your Mounjaro is dispensed by a registered pharmacy. The entire process from consultation to first dose usually takes 3–7 days.
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.