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 Stock and Availability in the UK
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private online prescribing. NICE approved tirzepatide for weight management in 2023, though NHS availability varies significantly by region due to demand and funding. Stock levels depend on your route of access—NHS specialist tier 3 services manage their own supplies, whilst private pharmacies maintain independent stock. Understanding your local NHS options and private alternatives can help you navigate the current prescribing landscape effectively.
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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.
How Mounjaro Availability Works in the UK
Mounjaro stock availability in the UK differs between NHS and private routes. NHS access is through specialist tier 3 weight management services, which hold their own supplies and manage prescriptions within ICB (Integrated Care Board) budgets. Availability varies significantly—some regions have waiting lists of several months, whilst others have more immediate access. Private access is through GPhC-registered online pharmacies, which typically maintain stock of common doses (5mg, 10mg, 15mg KwikPens) and can dispense following a clinical assessment with a UK-licensed prescriber. Private stock availability is generally more consistent than NHS stock.
- NHS stock depends on regional commissioning and demand
- Private pharmacies restock regularly to meet demand
- Mounjaro comes as pre-filled KwikPen devices (4 weeks supply per pen)
- Some areas have NHS waiting lists; private route offers faster access
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 Approval, NICE Guidance, and Current Status
NICE approved tirzepatide (Mounjaro) for weight management in January 2023, making it available on the NHS for eligible adults. However, NICE approval does not automatically mean unlimited NHS access—prescription depends on your local ICB's commissioning decisions and budget. Eligibility criteria include a BMI of 30 or above, or BMI of 27–29.9 with a weight-related health condition such as type 2 diabetes, hypertension, or cardiovascular disease. Your GP can refer you to tier 3 specialist services for assessment. Current demand for Mounjaro remains high across the UK, meaning NHS waiting times can be considerable in many areas. Private prescribing offers an alternative route if NHS waiting lists are lengthy.
- 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 available on the NHS in the UK?
Yes, NICE approved Mounjaro in January 2023. NHS availability is through tier 3 specialist weight management services, though access varies significantly by region due to budget constraints and demand. Your GP can refer you to your local service for assessment if you meet eligibility criteria.
What are the current stock issues with Mounjaro in the UK?
Mounjaro has experienced supply challenges globally, including in the UK. Private pharmacies generally maintain more consistent stock than NHS services. If NHS waiting times are long, private online prescribing with a UK-licensed prescriber offers faster access via GPhC-registered pharmacies, though at private cost.
How do I get Mounjaro on the NHS in my area?
Ask your GP for a referral to your local tier 3 weight management service (usually through your ICB). You'll need a BMI of 30 or above, or 27–29.9 with a weight-related condition. The specialist service will assess your eligibility and manage your prescription and supply through NHS stock.
What's the difference between NHS and private Mounjaro access?
NHS access is free but involves a GP referral, assessment by specialists, and potential waiting lists. Private access is faster—you complete an online consultation with a UK-licensed prescriber and collect from a GPhC-registered pharmacy—but you pay per prescription (typically £129–£320/month depending on dose).
Can I use our GLP-1 weight loss calculator to estimate Mounjaro results?
Yes. Our free GLP-1 weight loss calculator can help you estimate potential weight loss at different Mounjaro doses based on clinical trial data. This is useful for understanding expected outcomes whether you access Mounjaro through NHS or private routes.
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.