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 5mg Weight Loss: NHS Context and Real Results
Mounjaro 5mg is the first maintenance dose of this weekly weight loss injection, typically reached after 4 weeks of treatment in the UK. Clinical trials show that at this dose, patients lost an average of around 15% of their body weight alongside diet and exercise changes—though individual results vary significantly. This NHS-aligned guide explains what Mounjaro 5mg can realistically achieve, how NHS tier 3 specialist services prescribe it, and what the evidence actually shows about weight loss at this dose level.
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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 Eligibility and Mounjaro 5mg Prescribing in the UK
In the UK, Mounjaro is available through NHS specialist weight management services (tier 3) for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may qualify at lower BMI thresholds due to higher metabolic risk. The 5mg dose is typically the first standard maintenance dose—you start at 2.5mg and escalate weekly until reaching 5mg after week 4. NICE guidance supports tirzepatide (Mounjaro) within NHS specialist services, though regional availability and waiting times vary significantly across England, Scotland, Wales, and Northern Ireland.
- Prescription is through tier 3 services, not standard GP prescribing
- Requires clinical assessment of eligibility and health status
- 5mg is reached via dose titration over 4 weeks
- Regional NHS availability varies—some areas have lengthy waiting lists
Clinically BackedWeight Loss
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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.
What Weight Loss Results Does Mounjaro 5mg Achieve?
Clinical trial data (SURMOUNT-1) showed that at 5mg per week, patients lost an average of approximately 15% of their body weight over 72 weeks alongside a reduced-calorie diet and increased physical activity. However, this is an average—some people lost more, others less. Results depend on your starting weight, adherence to diet and exercise, genetics, and individual response. Our GLP-1 weight loss calculator can help you estimate potential weight loss ranges at different doses. Many NHS patients report that the 5mg dose effectively reduces appetite and food cravings, making it easier to maintain a calorie deficit. Always expect variation; weight loss is not assured, and your GP or prescriber will monitor your progress 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 5mg available on the NHS?
Yes—Mounjaro (tirzepatide) is available on the NHS through tier 3 specialist weight management services for eligible adults. Access varies by region; you'll typically be referred by your GP. Waiting times and availability depend on your local NHS integrated care board. Private prescription routes are also available via online assessment with a UK-licensed prescriber.
How does Mounjaro 5mg compare to Wegovy?
Mounjaro is a dual GIP and GLP-1 agonist; Wegovy is a GLP-1 agonist only. At 5mg Mounjaro, average weight loss was around 15% in trials; Wegovy at its maximum dose (2.4mg) showed similar results. Mounjaro escalates more aggressively (weekly up to 15mg). The choice depends on individual factors and prescriber assessment—there's no universally "better" option.
What side effects occur at the 5mg dose?
Common side effects at 5mg include nausea, diarrhoea, constipation, and reduced appetite. These usually improve as your body adjusts. Serious side effects are rare but include severe stomach pain (possible pancreatitis) or allergic reactions. Your prescriber will monitor you; report any concerning symptoms to your GP immediately.
Can I stay on Mounjaro 5mg, or do I have to keep increasing the dose?
You don't have to escalate beyond 5mg if it's working well and you're tolerating it. Some patients remain on 5mg long-term with good results. Others escalate to 10mg or higher for greater effect. Your prescriber will discuss the best dose for you based on your response, side effects, and health goals.
How long do I take Mounjaro 5mg before seeing weight loss results?
Weight loss typically begins within the first 2–4 weeks on 5mg, though the rate varies. Most patients see noticeable change by 8–12 weeks. You'll be monitored regularly by your NHS tier 3 service or private prescriber. Use our progress tracker to log weekly changes and discuss trends with your healthcare provider.
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.