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 a prescription-only weight loss injection available in the UK, but stock and availability vary significantly depending on where you seek treatment. If you're considering Mounjaro for weight management, it's important to understand the different routes to access it — whether through NHS specialist services or private prescription pathways — and what current availability looks like across the UK. This guide explains your options and what to expect.
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.
Where to Access Mounjaro in the UK
Mounjaro is available through two main routes in the UK:
- NHS specialist weight management services: If referred to a tier 3 or tier 4 specialist service by your GP, you may be assessed for Mounjaro. NICE has approved tirzepatide for NHS use, but access varies significantly by region (Integrated Care Board). Waiting lists can be very long — in some areas, several months to over a year. Availability depends on your local NHS funding and service capacity.
- Private prescription route: GPhC-registered online pharmacies can dispense Mounjaro following a consultation with a UK-licensed prescriber. This route typically has faster access than NHS, though stock levels vary between providers. Private prescriptions require a clinical assessment to confirm eligibility.
Stock availability fluctuates at both NHS and private providers. If one provider has limited stock, you may need to wait a few weeks or explore alternative providers.
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.
Current Availability and What to Do If Stock Is Limited
Mounjaro supply in the UK has improved significantly since its launch, but shortages can still occur, particularly at peak demand times. If you're struggling to find stock, consider:
- Contacting multiple private providers to compare availability
- Asking your NHS specialist service about expected wait times
- Discussing with your prescriber whether an alternative GLP-1 medication like Wegovy (semaglutide) might be suitable — both are UK-licensed for weight management, though results and mechanisms differ slightly
- Using our GLP-1 weight loss calculator to understand projected outcomes with either medication at different doses
Remember that Mounjaro works alongside lifestyle changes — diet and physical activity remain essential to weight management success.
- 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 long is the NHS waiting list for Mounjaro in the UK?
NHS waiting times vary by region and can range from several months to over a year, depending on your local Integrated Care Board. Contact your GP or weight management service for a specific estimate. Private prescription pathways typically offer faster access but involve costs.
Can I buy Mounjaro without a prescription in the UK?
No. Mounjaro is prescription-only in the UK and can only be dispensed following a clinical assessment by a licensed prescriber. Anyone offering Mounjaro without a prescription is operating illegally.
What is the cost of private Mounjaro in the UK?
Private Mounjaro costs typically range from £129–£320 per month depending on your dose (2.5 mg to 15 mg). Costs vary between providers. Always check with the prescriber and pharmacy for exact pricing before proceeding.
Is Mounjaro the same as Wegovy?
No. Both are UK-licensed weight loss injections, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show similar average weight loss (~15–21% for Mounjaro vs ~15% for Wegovy), though individual results vary significantly.
What should I do if Mounjaro is out of stock?
Contact your provider about expected restock dates. Consider exploring alternative providers, discussing Wegovy as an alternative with your prescriber, or checking your eligibility. Use our BMI calculator to confirm your current status and discuss options with your GP.
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.