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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How to Access Mounjaro in the UK
Mounjaro (tirzepatide) is available in the UK through both NHS and private routes, but access differs significantly depending on which pathway you choose. The NHS offers access through specialist weight management services, whilst private access is available through online prescribers following a clinical assessment. Understanding both routes helps you determine which option suits your circumstances. This guide explains current availability, eligibility criteria, and what to expect from each pathway in the UK health system.
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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 Access to Mounjaro in the UK
NICE approval and NHS availability: The National Institute for Health and Care Excellence (NICE) has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, NHS access is not available from your GP directly. Instead, you must be referred to a tier 3 or tier 4 specialist weight management service by your GP. These services are multidisciplinary teams based in hospitals or specialist clinics.
Regional variation: Availability varies significantly across England, Scotland, Wales, and Northern Ireland. Some areas have well-established services with shorter waiting lists, whilst others have limited capacity or very long waits. Your local Integrated Care Board (ICB) determines availability in your area.
- Ask your GP whether your local specialist weight management service offers Mounjaro
- Enquire about waiting times — these can range from months to over a year in some regions
- Check if your BMI and health conditions meet your local service criteria
The NHS route is free, but you'll need patience given current waiting list pressures across most areas.
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.
Private Access and How to Start Mounjaro
Private prescribing option: Mounjaro is also available through private online healthcare providers. You complete an online consultation with a UK-licensed prescriber, who assesses your suitability for treatment. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy. This route bypasses NHS waiting lists entirely.
Cost and timeline: Private treatment typically costs £150–£320 per month depending on dose and provider. You can usually start treatment within days of approval. Many people use the GLP-1 weight loss calculator to explore projected outcomes at different doses before committing.
Important: Private providers still require genuine clinical assessment—they will not prescribe without reviewing your health status, BMI, and any contraindications. Always use providers that are clearly regulated and transparent about their prescribing process.
- 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 I get Mounjaro on the NHS in my area?
Availability varies by region. Contact your GP and ask for referral to your local tier 3 specialist weight management service. They'll confirm whether Mounjaro is offered and what the current waiting time is. Not all areas have equal access due to NHS funding variations.
What BMI do I need to qualify for Mounjaro in the UK?
You typically need a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, or cardiovascular disease). South Asian, Chinese, Black African, and Black Caribbean adults may qualify at BMI 27.5 or above due to higher health risks at lower weights.
How long are NHS waiting lists for Mounjaro?
Waiting times vary significantly by region—from a few months to over a year in some areas. Your GP can give you a realistic estimate for your local service. Private access typically offers treatment within days of approval instead.
Is Mounjaro the same as Wegovy?
No. Both are prescription weight loss injections, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials showed slightly higher average weight loss with Mounjaro, but both are effective. Your prescriber will recommend the most suitable option for you.
Can my GP prescribe Mounjaro directly?
Not typically. GPs can prescribe some weight loss medications, but Mounjaro access usually requires referral to a specialist tier 3 weight management service. However, some specialist GP practices with enhanced commissioning may prescribe it—ask your GP whether they're able to. Private prescribers can also issue prescriptions without NHS referral.
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.