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 to Access Mounjaro Through UK Clinics
If you're considering Mounjaro (tirzepatide) for weight management in the UK, you have two main routes: NHS specialist weight management clinics or private online prescribing services. Both require a clinical assessment from a licensed prescriber, but they differ significantly in waiting times, availability, and cost. Understanding your options helps you make an informed decision about which pathway suits your circumstances. Use our free BMI calculator above to check whether you meet the basic eligibility criteria before exploring clinic options.
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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.
NHS Mounjaro Access — Tier 3 Weight Management Services
NHS access to Mounjaro happens through specialist tier 3 weight management clinics, not through standard GP appointments. Your GP can refer you to your local integrated care board (ICB) specialist service if you meet eligibility criteria: BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions like type 2 diabetes, hypertension, or sleep apnoea.
- Referral must come from your GP — you cannot self-refer to most NHS services
- Waiting lists vary by region; some areas have 12–24 month waits
- Once assessed, prescribers may start you on Mounjaro KwikPen at 2.5 mg, titrating weekly up to your maintenance dose
- Clinic monitoring includes regular blood tests, blood pressure checks, and dose adjustments
- NICE guidance confirms tirzepatide is cost-effective for NHS use in eligible patients
The dose titration schedule follows clinical protocols: you'll typically spend 4 weeks on each dose before escalation, meaning full therapeutic effect takes several months to achieve.
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 Mounjaro Clinics and Online Prescribing in the UK
Private prescribing offers faster access without NHS referral. Licensed UK prescribers assess your eligibility through online consultation, and if appropriate, issue a prescription dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 monthly depending on dose, compared to free NHS provision.
- Appointments available within days, not months
- Assessment covers medical history, current medications, and contraindications
- KwikPen prescriptions begin at 2.5 mg with standard NHS-aligned titration guidance
- Private providers often offer follow-up support and progress tracking
Try our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, which may help you discuss options with your prescriber. Whether NHS or private, consistent diet and exercise changes are essential for optimal 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.
Can I get Mounjaro through my GP without a referral to a weight management clinic?
No. Standard GPs do not prescribe Mounjaro on the NHS. You must be referred by your GP to a tier 3 specialist weight management service, which then assesses and prescribes if appropriate. Private online prescribers, however, do not require an NHS referral.
How long does it take to get Mounjaro through an NHS clinic?
NHS waiting times vary significantly by region, ranging from 6 months to 2 years or longer in some areas. Private prescribing typically offers appointments within 7–14 days, making it faster if you cannot wait for NHS services.
What happens at a Mounjaro clinic appointment?
Your prescriber will assess your BMI, weight-related health conditions, current medications, and any contraindications. Blood tests may be taken to check liver and kidney function. If approved, you'll receive Mounjaro KwikPen and injections instructions, starting at 2.5 mg with weekly dose increases as tolerated.
Does the NHS cover the cost of Mounjaro if I get it privately?
No. If prescribed privately, you pay for the full cost yourself. NHS provision is free to eligible patients, but access is through specialist tier 3 services only, not private pharmacies. Once prescribed privately, the NHS will not cover ongoing costs.
What is the difference between Mounjaro and Wegovy at a UK clinic?
Both are once-weekly injections for weight management, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is GLP-1 only. Mounjaro often achieves slightly higher weight loss in trials (~20% vs ~15%), but both require prescription and clinical assessment through the same NHS or private clinic pathways.
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.