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
How Do I Get Mounjaro in the UK?
Getting Mounjaro in the UK involves two main routes: NHS prescription through specialist weight management services, or private prescription following an online clinical assessment. The NHS route is free but involves lengthy waiting lists in most areas. Private access is faster and more widely available, with costs typically ranging from £129 to £320 per month depending on your dose. Both routes require a prescription from a UK-licensed healthcare professional and a clinical assessment to confirm you're eligible. This guide explains how each route works, what to expect, and the real costs involved.
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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.
Private Route: Cost and How to Access Mounjaro
The private route to Mounjaro is the fastest way to start treatment in the UK. You can access tirzepatide through GPhC-registered online pharmacies without a NHS referral. The process involves a brief online consultation with a UK-licensed prescriber who reviews your health history, BMI, and any weight-related conditions to assess whether Mounjaro is appropriate for you.
Typical private costs:
- Starter doses (2.5mg–5mg): approximately £129–£180 per month
- Mid-range doses (7.5mg–10mg): approximately £200–£250 per month
- Higher doses (12.5mg–15mg): approximately £280–£320 per month
Costs vary by provider and dose frequency. Your KwikPen contains 4 weeks' supply at your prescribed dose. Once approved, medication is dispensed by post to your home address. No NHS waiting list is involved, so you could start within days of your clinical assessment. Use our GLP-1 weight loss calculator to estimate potential results at different doses before you start.
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 Route vs Private: Which Path Is Right for You?
The NHS provides free Mounjaro through tier 3 specialist weight management services, but access varies significantly by region and involves substantial waiting lists—often 6–24 months depending on your area. You must be referred by your GP and meet strict eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions like type 2 diabetes or hypertension). NICE has approved tirzepatide for NHS use, but availability depends on your Integrated Care Board's budget and local commissioning decisions.
The private route offers faster access (days rather than months), no NHS referral needed, and assured availability. However, you pay out of pocket at approximately £1,500–£3,800 per year depending on your dose. The online consultation process is straightforward: complete a health questionnaire, speak briefly with a prescriber, receive your prescription, and collect your medication from a pharmacy. Both routes require genuine clinical assessment—Mounjaro is prescription-only and not available without one.
- 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 quickly can I start Mounjaro privately in the UK?
Private prescription typically takes 24–48 hours from your online consultation to approval. Your first KwikPen can be dispensed and posted within 3–5 working days. You could be injecting your first dose within a week, compared to NHS waiting lists of many months.
Will my GP refer me to the NHS for Mounjaro?
Your GP can refer you to NHS tier 3 weight management services, but this doesn't assures Mounjaro access—it depends on your regional commissioning. Ask your GP about local availability. Many GPs are unaware of current availability due to regional variation and competing priorities.
What happens in the private online consultation?
You complete a health questionnaire covering weight, medical history, medications, and weight-related conditions. A UK-licensed prescriber reviews your form, assesses eligibility, and discusses whether Mounjaro suits you. The entire process takes 15–30 minutes. If approved, your prescription is issued to a pharmacy within hours.
Can I switch between NHS and private Mounjaro?
Technically yes, but it's complex. If you start privately and later access NHS treatment, your prescriber will manage the transition. Conversely, if you're on the NHS waiting list and start privately, inform your GP to avoid duplication. Always tell any healthcare provider about existing weight loss medication.
Is Mounjaro cheaper on the NHS or private?
NHS Mounjaro is free at point of use (no prescription charge). Private costs £129–£320/month depending on dose. However, many people choose private due to NHS waiting lists of 12+ months. Your decision depends on how urgently you want to start and whether you can access NHS services in reasonable time.
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.