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 Results in the UK: Cost, Access & Outcomes
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private online prescribing routes, though access, costs, and results vary significantly depending on which pathway you choose. Understanding the realistic outcomes, eligibility criteria, and what you'll actually pay is essential before starting treatment. This guide covers UK access options, typical costs, and what clinical evidence tells us about real-world results with Mounjaro in the UK context.
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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.
Mounjaro Cost in the UK: NHS vs Private Access
NHS access: Mounjaro is available on the NHS through tier 3 specialist weight management services following NICE approval. However, NHS access is limited by regional availability and waiting lists — many areas have waiting times of 6–18 months or longer. Your GP would need to refer you to a specialist weight management service, which then assesses eligibility and prescribes if appropriate. Once approved, the NHS covers the full cost.
Private access costs: Through private online prescribing in the UK, Mounjaro typically costs between £130–£300 per month depending on the dose and provider. Starting doses (2.5 mg) are usually at the lower end; maintenance doses (10–15 mg) are at the higher end. Each KwikPen contains 4 weeks of doses. Costs are paid privately — there is no NHS cost if you choose private prescribing.
- Starting dose (2.5 mg): typically £130–£150/month
- Maintenance doses (5–10 mg): typically £180–£240/month
- Maximum dose (15 mg): typically £260–£300/month
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.
Real Results: Clinical Evidence & What to Expect
Clinical trials (SURMOUNT-1) showed that people using Mounjaro lost an average of 15–21% of their body weight over 72 weeks, alongside a reduced-calorie diet and increased physical activity. However, individual results vary significantly — some people lose more, others less. Weight loss typically begins within 2–4 weeks, with most noticeable changes by weeks 8–12 as doses increase.
Important: Mounjaro is not a structured approach. Results depend on adherence to the medication, dietary changes, and increased physical activity. If you stop taking Mounjaro, weight often returns. Using our free GLP-1 weight loss calculator can help you estimate potential results at different Mounjaro doses based on clinical trial data.
What affects your personal results: Your starting weight, age, metabolism, diet quality, exercise level, and genetics all influence how much weight you lose. Some people respond better to tirzepatide (Mounjaro's active ingredient) than others — this is why a prescriber will assess whether this medication suits you individually. South Asian, Chinese, Black African, and Black Caribbean adults may qualify for treatment at lower BMI thresholds due to higher health risks at lower weights.
Calculate your BMI using our free BMI calculator above to understand your starting point and eligibility for prescription weight loss treatment in the UK.
- 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 much weight will I lose on Mounjaro in the UK?
Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks. Individual results vary significantly. Your personal loss depends on starting weight, dose, adherence, diet quality, exercise, and metabolism. Always discuss realistic expectations with your prescriber — they can give personalised guidance based on your health profile.
Is Mounjaro available on the NHS in the UK?
Yes, Mounjaro is approved by NICE for NHS use through tier 3 specialist weight management services. However, NHS availability is limited by region and waiting lists can be very long (6–18+ months). Your GP would refer you to a specialist service for assessment. Private prescribing is available without NHS referral if you prefer faster access.
What's the difference between NHS and private Mounjaro access in the UK?
NHS access is free but involves GP referral, specialist assessment, and potential waiting lists. Private prescribing is faster (online consultation to prescription in days) but costs £130–£300/month depending on dose. Both require a valid prescription from a UK-licensed prescriber and clinical assessment.
How long before I see Mounjaro results?
Most people notice appetite changes within 1–2 weeks. Visible weight loss typically begins within 2–4 weeks. More significant results appear by weeks 8–12 as doses increase toward maintenance levels. Results are gradual and depend on diet, exercise, and adherence to injections.
Can I get Mounjaro on prescription without seeing my GP?
Yes, through private online prescribing. A UK-licensed prescriber reviews your health via an online consultation, and if suitable, issues a prescription dispensed by a GPhC-registered pharmacy. You do not need an NHS referral for private prescribing — though you must still have a valid clinical assessment before prescription.
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.