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
Mounjaro 5mg and NHS Weight Management in the UK
Mounjaro 5mg is the standard maintenance dose of tirzepatide, a dual GIP and GLP-1 receptor agonist injection licensed for weight management in UK adults. Access through the NHS involves referral to specialist tier 3 weight management services, though availability varies significantly by region. This guide explains NHS eligibility, how the 5mg dose works in clinical practice, and what to expect from the prescribing pathway in the UK.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Eligibility and the 5mg Maintenance Dose
In the UK, Mounjaro 5mg is typically the first maintenance dose after the initial titration phase (2.5mg weeks 1–4). NHS eligibility for Mounjaro requires either 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, high blood pressure, abnormal blood fats, or cardiovascular disease. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may qualify at lower BMI thresholds due to higher health risks at these levels.
In clinical trials, the 5mg dose supported average weight loss of approximately 15% body weight when combined with reduced-calorie diet and increased physical activity. Individual results vary significantly. Most patients remain on 5mg for several weeks before NHS specialists consider escalation to higher doses (7.5mg, 10mg, 15mg) based on response and tolerance.
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 Access Pathway and Regional Variation
NHS access to Mounjaro works through tier 3 specialist weight management services. Your GP cannot routinely prescribe Mounjaro directly—referral to a specialist service is required, usually following completion of tier 1 or tier 2 weight management interventions. Regional Integrated Care Boards (ICBs) determine availability, and waiting lists for specialist assessment vary considerably across the UK, from weeks to many months in high-demand areas.
Once assessed and started on Mounjaro through NHS specialist services, dose titration and monitoring occur within that service. Use our free BMI calculator and GLP-1 weight loss calculator to understand your starting point and potential outcomes before your NHS appointment. Many patients also track progress using our free progress tracker throughout their weight management journey.
- 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 my GP prescribe Mounjaro 5mg directly on the NHS?
No. Mounjaro is prescribed through NHS tier 3 specialist weight management services, not by GPs. You need a referral from your GP to access these services. Your GP cannot issue an NHS prescription for Mounjaro without specialist assessment and recommendation.
How long does it take to reach the 5mg dose on the NHS?
The standard titration schedule is 2.5mg for weeks 1–4, then 5mg from week 5 onwards. So you reach the 5mg maintenance dose after approximately four weeks of treatment, assuming no tolerability issues requiring slower titration.
What is the difference between Mounjaro 5mg and Wegovy for NHS access?
Both are GLP-1-based weight loss injections, but Mounjaro is a dual GIP/GLP-1 agonist whilst Wegovy is GLP-1 only. NHS access differs by region and specialist service—some services may offer one, both, or neither depending on local commissioning and availability.
Will the NHS cover Mounjaro 5mg if I have a BMI of 27?
Yes, if your BMI is 27–29.9 and you have at least one weight-related health condition (diabetes, high blood pressure, heart disease, etc.). If your BMI is below 27, NHS prescribing is unlikely unless you have multiple significant health comorbidities.
How is the 5mg dose given, and how often?
Mounjaro 5mg is a once-weekly injection using a pre-filled KwikPen. You inject under the skin (abdomen, thigh, or upper arm) once every seven days. The pen delivers a fixed 5mg dose and is designed for self-administration after initial training.
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.