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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Weight Plateau on Mounjaro — How to Access Support in the UK
A weight plateau on Mounjaro is common and doesn't mean the medication has stopped working — your body may simply be adjusting. Understanding your UK access options, whether through the NHS or private prescription routes, helps you explore next steps with your healthcare provider. This guide covers realistic costs, how to obtain Mounjaro in the UK, and what happens when weight loss slows down.
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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.
Accessing Mounjaro in the UK — Cost and Prescription Routes
In the UK, Mounjaro (tirzepatide) is a prescription-only medicine available through two main routes. Private online prescribing typically costs between £129 and £320 per month depending on your dose, with pricing usually per pen (a 4-week supply). The cost reflects the dose strength — higher doses cost more. A starting dose (2.5 mg) will be cheaper than a maintenance dose like 10 mg or 15 mg. NHS access goes through specialist tier 3 weight management services via GP referral, though regional availability varies significantly and waiting lists can be lengthy. Private prescriptions are dispensed by GPhC-registered pharmacies following an online clinical assessment. You'll need to provide medical history, current medications, and weight/height information. The prescriber will assess suitability before issuing a prescription. Most online consultations cost £25–£50 and are typically deducted from your first medication supply.
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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.
Weight Plateaus and Dose Adjustment — What You Need to Know
Weight plateaus during Mounjaro dose titration are normal as your body adapts. Most people stay on each dose for a minimum of 4 weeks before increasing, and plateaus often resolve as your body continues to adjust. If weight loss truly stalls after 8–12 weeks on a stable dose, your prescriber may suggest increasing to the next dose level — for example, from 5 mg to 7.5 mg or from 10 mg to 12.5 mg. Dose adjustments are managed by your prescriber, whether NHS or private. Combined with a reduced-calorie diet and increased physical activity, many people experience renewed progress. Our free GLP-1 weight loss calculator can help you estimate potential outcomes at different dose levels, and our progress tracker lets you monitor changes over weeks and months rather than focusing on daily fluctuations.
- 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 does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129–£320 per month depending on dose strength. A starting 2.5 mg dose is cheaper; higher doses (10 mg, 15 mg) cost more. Each pen supplies 4 weeks of once-weekly injections. Prices vary slightly between online prescribing providers. An online consultation usually costs £25–£50 and is often deducted from your first medication supply.
Can I get Mounjaro free on the NHS?
Mounjaro is available on the NHS through specialist tier 3 weight management services, but access varies significantly by region and waiting lists can be very long. You'll need a GP referral to specialist services. NHS availability depends on your local ICB (Integrated Care Board) and their commissioning decisions. Your GP can advise whether you're eligible and the current pathway in your area.
What happens if I hit a weight plateau on Mounjaro?
Weight plateaus are common and don't mean the medication has stopped working. If weight loss slows after weeks on a stable dose, your prescriber may suggest increasing to the next dose level. Ensure you're maintaining a reduced-calorie diet and increasing physical activity, as Mounjaro works best alongside lifestyle changes. Some plateaus resolve naturally as your body adapts.
How long does it take to access Mounjaro privately?
Private online prescriptions are typically processed within 24–48 hours of completing your clinical assessment. You'll receive your prescription electronically and the medication is usually dispensed within 2–3 working days. NHS access is slower due to referral pathways and specialist waiting lists, which vary from weeks to many months depending on your region.
Can I switch between NHS and private Mounjaro?
Switching between NHS and private routes is possible but requires coordination with your healthcare providers. If you're already on Mounjaro privately and want NHS access, discuss this with your GP. If you're on the NHS and want to switch to private, you can start a private prescription — though you should inform your NHS team. Never stop and restart without medical guidance, as there's a minimum 72-hour gap between doses.
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.