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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What Do Mounjaro Reviews Say? NHS & UK Evidence Guide
Mounjaro (tirzepatide) is a prescription-only GLP-1 receptor agonist and GIP receptor agonist approved by the MHRA for weight management in UK adults. You'll find mixed reviews online, but the most reliable information comes from NHS guidance, NICE approval, and clinical trial data like the SURMOUNT studies. This guide covers what real Mounjaro experience looks like in the NHS and private setting, eligibility criteria, and what the evidence actually shows — helping you understand whether this weekly weight loss injection might be right for you.
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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 & Clinical Evidence in the UK
NHS prescribing context: Mounjaro is now approved by NICE for use within NHS specialist weight management services (tier 3 and tier 4). However, NHS access varies significantly by region, and waiting lists can be lengthy in many areas. Most reviews from NHS users mention months-long waits before their first appointment.
Clinical trial data: The SURMOUNT-1 trial showed participants on 15 mg tirzepatide lost an average of 20.9% body weight over 72 weeks alongside dietary changes and physical activity — though individual results varied considerably. Doses of 5 mg and 10 mg showed average losses of around 15% and 19.5% respectively.
- MHRA approved for BMI ≥30, or BMI 27–29.9 with weight-related health conditions
- South Asian, Chinese, Black African, and Caribbean adults may qualify at lower BMI thresholds
- Requires clinical assessment — not suitable for all adults
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 vs Private Mounjaro Access: What Reviewers Report
Real user reviews highlight two distinct UK experiences. NHS route: Free once prescribed, but involves GP referral to specialist services, lengthy waiting periods, and limited dose availability in some regions. Reviews often mention three to twelve-month waits.
Private route: Faster access through online clinical assessments with UK-licensed prescribers, costs £129–£320+ per month depending on dose, and available without NHS referral. Many reviewers choose private access due to NHS waiting times.
Both routes require genuine clinical assessment — prescribers will check your BMI, health history, and suitability. Track your progress with our free progress tracker to monitor results over time.
- 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.
Is Mounjaro approved by the NHS in the UK?
Yes. NICE approved tirzepatide (Mounjaro) for NHS use within tier 3 specialist weight management services. However, availability and access vary by region, with significant waiting lists in many areas. Your GP can refer you to your local NHS specialist service if you meet eligibility criteria.
What do real Mounjaro reviews say about side effects?
Common side effects mentioned in reviews include nausea, diarrhoea, constipation, and stomach discomfort — especially in the first weeks. Most reviewers report these reduce over time. Serious side effects are rare but include pancreatitis symptoms (severe stomach pain) and gallbladder problems. Always report any concerning symptoms to your prescriber.
How much weight do people actually lose on Mounjaro?
Clinical trial data shows an average loss of 15–21% body weight depending on dose — but individual results vary widely. Mounjaro is not assured to produce weight loss; it works best alongside a reduced-calorie diet and physical activity. Our GLP-1 weight loss calculator can help estimate potential results based on your starting point.
What's the difference between NHS and private Mounjaro in the UK?
NHS Mounjaro is free once prescribed but involves waiting lists and regional availability limits. Private Mounjaro requires online clinical assessment and costs £129–£320+ monthly but offers faster access. Both require genuine clinical assessment and ongoing prescriber support.
Should I choose Mounjaro or Wegovy based on reviews?
Both are GLP-1-based weight loss injections, but Mounjaro is a dual GIP + GLP-1 agonist while Wegovy is GLP-1-only. Clinical data shows similar average weight loss (~15–21% for Mounjaro, ~15% for Wegovy), but results vary individually. Your prescriber will advise which suits your health profile.
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.