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
Who Qualifies for Mounjaro in the UK?
Eligibility for Mounjaro (tirzepatide) in the UK is determined by your BMI and whether you have weight-related health conditions. Access depends on whether you pursue NHS specialist services or private prescription through an online consultation. Understanding your eligibility and the available routes is essential before starting. This guide covers NHS and private pathways, costs, and what to expect during the qualification process.
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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.
UK Eligibility Criteria and Access Routes
Standard eligibility for Mounjaro: You may qualify 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, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or a history of heart attack or stroke.
Ethnicity-adjusted thresholds: If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recognises lower BMI thresholds (from 27.5 kg/m²) due to higher cardiovascular and metabolic risk at lower weights.
Two access routes: NHS route: Referral to a tier 3 specialist weight management service through your GP. Availability and waiting times vary significantly by region. Private route: Online consultation with a UK-licensed prescriber, prescription issued if clinically appropriate, dispensed by a GPhC-registered pharmacy. No NHS referral required.
Use our free BMI calculator above to check your starting point and understand your eligibility category.
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 Prescription Cost and What to Expect
Private Mounjaro prescriptions in the UK typically cost £129–£320 per month, depending on the dose you are prescribed. Starting doses (2.5 mg) are usually at the lower end; higher doses (10–15 mg) are at the higher end. Costs include the prescription assessment, the prescription itself, and dispensing. Some providers offer dose-bundled pricing or monthly subscription models.
What to expect: Online consultation with a UK-licensed prescriber (15–30 minutes), medical history review, assessment of your BMI and health conditions, discussion of side effects and contraindications, and a prescription issued directly if approved. No waiting lists. You receive your first KwikPen within 2–5 working days. Try our GLP-1 weight loss calculator to estimate projected outcomes at different doses before committing.
Private Mounjaro prescriptions in the UK typically cost £129–£320 per month, depending on your prescribed dose. Starting doses (2.5 mg) are usually cheaper; maintenance doses (10–15 mg) cost more. Prices include the online consultation with a prescriber, the prescription itself, and pharmacy dispensing. Some providers offer bundled pricing models or subscription discounts for longer commitments.
What the private process looks like: You complete an online medical questionnaire, have a brief consultation with a UK-licensed prescriber (typically 15–30 minutes), discuss your weight loss goals and medical history, review potential side effects and contraindications, and receive a prescription if approved. Your first KwikPen arrives within 2–5 working days. Try our GLP-1 weight loss calculator to estimate projected weight loss outcomes at different doses before proceeding.
- 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 BMI do I need to qualify for Mounjaro?
You typically qualify if your BMI is 30 or above, or 27–29.9 with a weight-related health condition like type 2 diabetes or high blood pressure. Use our BMI calculator to check your current BMI instantly. If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, lower thresholds (from 27.5) may apply due to higher health risks at lower weights.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs range from approximately £129–£320 per month depending on your dose. Starting doses (2.5 mg) are cheaper; higher maintenance doses (10–15 mg) cost more. This includes the online prescription assessment, prescriber consultation, and pharmacy dispensing. Prices vary slightly between providers.
Can I get Mounjaro on the NHS in the UK?
Mounjaro is available through NHS tier 3 specialist weight management services if you meet clinical criteria and are referred by your GP. However, NHS access is limited by regional availability and waiting lists can be very long (often months to years in some areas). Your GP can assess whether a referral is appropriate for you.
How do I access Mounjaro through a private prescription?
Complete an online medical questionnaire, have a brief consultation with a UK-licensed prescriber (15–30 minutes), and receive a prescription if approved. Your first KwikPen arrives within 2–5 working days. No NHS referral is needed. A prescriber will review your BMI, health conditions, and medications to assess suitability before issuing a prescription.
How does Mounjaro compare to Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials showed Mounjaro may produce slightly greater average weight loss (around 20.9% body weight at maximum dose versus 14.9% for Wegovy), though results vary. Both are prescription-only and both cost similarly via private prescription in the UK.
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.