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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Mounjaro on the NHS for Weight Loss — How to Access It
Mounjaro (tirzepatide) is now approved by NICE and available on the NHS for weight management, but access is limited to specialist tier 3 weight management services and varies significantly by region. If you're considering this weekly weight loss injection, understanding the NHS pathway versus private options can help you make an informed decision about how to access treatment. This guide covers NHS eligibility, what to expect, costs, and alternatives available in the UK today.
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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 Access to Mounjaro: Eligibility and the Specialist Pathway
NICE approved Mounjaro for NHS use in 2024, making it available through specialist weight management services rather than standard GP prescriptions. However, NHS access depends on referral to a tier 3 or tier 4 specialised weight management service, which requires your GP to believe you meet clinical criteria.
You may be eligible if you have:
- BMI of 30 kg/m² or above, or BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease)
- South Asian, Chinese, Black African, or Caribbean heritage (lower thresholds may apply — eligibility from BMI 27.5+)
- Previously attempted weight loss through diet and exercise
Regional variation is significant — some areas have waiting lists exceeding 18 months, whilst others have more immediate access. Your GP can tell you about availability in your local Integrated Care Board (ICB) area. Use our free GLP-1 weight loss calculator to explore potential outcomes with Mounjaro at different doses whilst you wait.
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 vs NHS: Cost, Speed, and What to Expect
The NHS route is free but can involve long waiting times. Private access to Mounjaro is available through online clinics following a consultation with a UK-licensed prescriber — results are typically available within 24–48 hours. Costs range from approximately £130–£300 per month depending on your dose and the provider you choose.
Private consultations assess your BMI, medical history, and suitability before issuing a prescription. You collect your Mounjaro KwikPen from a GPhC-registered pharmacy. Use our BMI calculator above to check your personal BMI before consultation — this helps your prescriber assess eligibility quickly. Both routes require a prescription; neither is available over the counter. Private access avoids NHS waiting lists but involves upfront cost.
- 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 on the NHS without a referral?
No. Mounjaro on the NHS requires a referral from your GP to a specialist tier 3 weight management service. Standard GP practices do not prescribe it. You cannot access NHS Mounjaro directly — your GP must refer you, and you must meet local eligibility criteria. Private routes avoid this requirement.
How long is the NHS waiting list for Mounjaro?
Waiting times vary dramatically by region. Some areas have waits of 6–12 months, others 18+ months or longer. Contact your local Integrated Care Board (ICB) or ask your GP about current waiting times in your area. Demand significantly exceeds current NHS supply across most regions.
What's the typical cost of Mounjaro privately in the UK?
Private prescriptions typically cost £130–£320 per month depending on your dose (2.5 mg to 15 mg weekly). Each KwikPen contains 4 weekly injections. Prices vary between private providers. Some offer payment plans. Always confirm total cost before starting treatment.
Is Mounjaro cheaper on prescription than privately?
Yes — on the NHS, Mounjaro is free. Privately, you pay per dose/month. However, the NHS route involves potential waiting times of months or years, whilst private access is typically available within 48 hours. Cost vs speed is a personal decision.
What happens at a private Mounjaro consultation?
You complete an online health questionnaire covering BMI, medical history, medications, and weight loss goals. A UK-licensed prescriber reviews this and may ask follow-up questions. If approved, they issue a prescription to a GPhC-registered pharmacy for collection or delivery. The whole process typically takes 24–48 hours.
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.