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 Do You Get Mounjaro in the UK?
Getting Mounjaro in the UK requires a prescription from a licensed healthcare provider following a clinical assessment. You can access Mounjaro through either NHS specialist weight management services or private online prescribing platforms. This guide explains both routes, eligibility criteria, and how Mounjaro's access process compares to Wegovy, another popular GLP-1 weight loss injection. Whether you're exploring NHS options or private alternatives, understanding the differences between these medications and how to obtain them can help you make an informed decision about your weight management journey.
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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.
NHS vs Private Routes — How Access Works
NHS access to Mounjaro: NICE has approved tirzepatide (Mounjaro) for use within NHS specialist tier 3 and tier 4 weight management services. You'll need a referral from your GP to a specialist service, where a multidisciplinary team assesses your eligibility. NHS access is free but involves waiting lists that vary significantly by region — some areas have waits of several months or longer. Availability depends on your local Integrated Care Board (ICB) funding decisions.
Private access to Mounjaro: You can obtain a prescription through GPhC-registered online prescribing services without NHS referral. A UK-licensed prescriber reviews your health information and medical history via an online assessment, and if appropriate, issues a prescription that a pharmacy dispenses. Private access is faster (often within days) but involves costs ranging from approximately £129–£240 per month depending on your dose. Both routes require a valid prescription — Mounjaro is prescription-only and cannot be bought without clinical assessment.
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.
Mounjaro vs Wegovy — Key Differences in Access & Mechanism
Both Mounjaro and Wegovy are prescription-only weight loss injections licensed in the UK, but they work differently and have distinct access pathways. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist — it activates two hormone pathways — whilst Wegovy (semaglutide) activates GLP-1 only. Clinical trials showed Mounjaro helped participants lose an average of approximately 20.9% body weight at maximum dose, whilst Wegovy showed approximately 14.9% average weight loss. Both are available through NHS specialist services and private prescribing, though availability and waiting times differ. Your GP or prescriber will assess which medication suits your individual health profile, medical history, and weight management goals. Individual results vary significantly, and either medication is typically used alongside a reduced-calorie diet and increased physical activity for best results.
- 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 are the eligibility criteria to get Mounjaro in the UK?
You may be eligible for Mounjaro if you have a BMI of 30 kg/m² or above, or a BMI of 27–29.9 kg/m² with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea). Adults of South Asian, Chinese, Black African, or Black Caribbean descent may qualify at slightly lower BMI thresholds. A prescriber will assess your individual circumstances.
How long does it take to get Mounjaro on the NHS?
NHS waiting times vary significantly by region. After GP referral to a specialist weight management service, you may wait from several weeks to over a year depending on your local ICB's funding and service capacity. Private prescribing is typically faster — often within days to a week of online assessment. Your GP can tell you about local NHS waiting times.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129–£240 per month depending on your dose and the prescribing service. Starting doses (2.5 mg) are usually cheaper than maximum doses (15 mg). Costs may vary between different online pharmacy providers, so it's worth comparing. NHS access is free but involves waiting lists.
Is Mounjaro the same as Wegovy?
No. Both are prescription-only weight loss injections, but Mounjaro (tirzepatide) uses a dual GIP+GLP-1 mechanism, whilst Wegovy (semaglutide) uses GLP-1 only. Clinical trial data showed different average weight loss outcomes. Your prescriber will recommend which is most suitable based on your health profile and individual circumstances.
Can I get Mounjaro without going to my GP?
Yes, through private online prescribing platforms. A UK-licensed prescriber can issue a prescription following an online assessment without an NHS referral. However, your GP is a useful first point of contact to discuss weight management options, check your eligibility, and understand your local NHS options before pursuing private routes.
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.