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
Can I Buy Mounjaro in the UK?
Yes, Mounjaro (tirzepatide) is available in the UK for weight management, but access depends on where you obtain it. You can access Mounjaro through NHS specialist tier 3 weight management services, though availability varies significantly by region and waiting lists can be lengthy. Alternatively, you can obtain a prescription through private online prescribing services following a clinical assessment. Both routes require a prescription from a UK-licensed healthcare professional. Use our free BMI calculator to check if you meet the typical eligibility criteria of BMI 30 or above, or BMI 27 and above with weight-related health conditions.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
NHS Access to Mounjaro in the UK
NHS access to Mounjaro has been approved by NICE (National Institute for Health and Care Excellence) for use within specialist weight management services. However, availability is limited and varies significantly across different regions and integrated care boards.
- Referral required: You must be referred to a tier 3 or tier 4 specialist weight management service by your GP — Mounjaro is not prescribed in primary care
- Eligibility: You typically need a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea
- Regional variation: Some NHS regions have active Mounjaro services; others have waiting lists of several months or longer, or may not yet offer it
- Assessment process: If accepted onto an NHS programme, you will undergo a full clinical assessment, health checks, and nutritional counselling before starting
Contact your GP surgery to ask whether Mounjaro is available through your local NHS weight management service.
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.
Private Access to Mounjaro in the UK
Mounjaro is also available privately through UK-registered online prescribing services. A GPhC-registered prescriber will review your medical history via an online consultation, and if clinically appropriate, issue a prescription dispensed by a UK pharmacy.
- No NHS referral needed: You can access private prescribing directly without waiting for NHS services
- Cost: Private Mounjaro costs approximately £129–£250+ per month depending on dose and provider
- Clinical assessment: You must still complete a medical questionnaire and consultation — prescribers will not issue prescriptions without proper assessment
- Dose titration: Treatment follows the same dose escalation as NHS prescribing, starting at 2.5 mg and increasing weekly based on tolerance
Private access offers faster availability but at a higher cost than NHS provision. Try our GLP-1 weight loss calculator to explore projected weight loss outcomes at different Mounjaro doses.
- 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 available on the NHS in the UK?
Yes, Mounjaro (tirzepatide) is approved by NICE for NHS specialist weight management services. However, availability varies significantly by region. You will need a GP referral to a tier 3 specialist service. Waiting times can be several months in some areas. Contact your GP to check whether Mounjaro is available locally.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs approximately £129–£250+ per month depending on the dose. A 2.5 mg pen (4 weeks) typically costs around £129–£150, while higher doses such as 15 mg may cost £200–£250+. Prices vary by provider. You will need a prescription from a UK-licensed prescriber.
Do I need a prescription to buy Mounjaro in the UK?
Yes, Mounjaro is a prescription-only medicine in the UK. You cannot purchase it without a valid prescription from a UK-licensed healthcare professional (GP, specialist, or licensed online prescriber). Prescriptions must be issued following a clinical assessment of your health history.
What is the difference between NHS and private Mounjaro?
The medication is identical. The difference is access and cost. NHS prescribing is free but involves waiting lists and specialist referral. Private prescribing is faster but costs £129–£250+ per month. Both routes require clinical assessment and prescription from a UK-licensed prescriber.
Do I need a BMI of 30 to get Mounjaro on the NHS?
A BMI of 30 or above is the standard threshold, but you may be eligible at BMI 27–29.9 if you have weight-related health conditions such as type 2 diabetes, high blood pressure, sleep apnoea, or cardiovascular disease. Eligibility criteria are assessed individually by NHS specialist services. Use our free BMI calculator to check your current BMI.
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.