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 Availability in the UK: NHS and Private Access
Mounjaro (tirzepatide) is available in the UK through both NHS specialist weight management services and private prescribing routes. Access depends on your BMI, health conditions, and which pathway you choose. NHS availability is limited to tier 3 specialist services with significant regional variation, whilst private prescribing through registered online services offers faster access without referral. Understanding your eligibility and the differences between routes can help you explore your options with your GP.
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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 and Eligibility Criteria
NICE approval: Mounjaro (tirzepatide) was approved by NICE in 2024 for use within NHS specialist weight management services, making it available on the NHS for eligible adults. However, NHS access is limited to tier 3 and tier 4 specialist weight management services — not through standard GP prescriptions.
Eligibility for NHS Mounjaro: You may be eligible if you have a BMI of 30 kg/m² or above, or BMI 27–29.9 kg/m² with at least one weight-related health condition such as type 2 diabetes, hypertension, or cardiovascular disease. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds apply (from BMI 27.5). Use our free BMI calculator above to check your starting point.
NHS specialist referral: You'll need a referral from your GP to a tier 3 weight management service. Waiting times vary significantly by region (Integrated Care Board). Many areas have lengthy waiting lists — sometimes 6–18 months or longer.
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 Mounjaro Access and UK Prescribing Routes
Private prescribing route: Mounjaro is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. This route does not require NHS referral and is typically faster than NHS access — often available within days to weeks.
Cost and dosing: Private prescriptions typically cost £129–£320 per month depending on dose. Mounjaro begins at 2.5 mg weekly and titrates up to a maximum of 15 mg, with each KwikPen containing 4 doses. Try our GLP-1 weight loss calculator to estimate potential outcomes at different doses based on clinical trial data.
Private vs NHS: The medication itself is identical — the difference is access speed, cost, and whether specialist NHS oversight is involved. Private prescribers must still conduct a proper clinical assessment to confirm suitability.
- 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 my area?
Mounjaro is now NICE-approved for NHS use, but availability depends on your local Integrated Care Board (ICB). Not all areas offer it yet, and most have waiting lists. Contact your GP to ask if your local NHS tier 3 weight management service has it in stock. Waiting times vary from several months to over a year in many regions.
What's the difference between a Mounjaro KwikPen and the prescription?
A Mounjaro KwikPen is the injectable device itself — a pre-filled pen that holds 4 weekly doses. Your prescription specifies the mg dose (2.5 mg, 5 mg, 7.5 mg, etc.). Each pen lasts 4 weeks, then you receive the next pen at your higher dose as you titrate up the protocol.
Can I switch from Wegovy to Mounjaro on the NHS?
Switching between weight loss injections is possible but must be managed by your prescriber. Mounjaro (a dual GIP/GLP-1 agonist) works slightly differently from Wegovy (GLP-1 only). If you're on Wegovy and want to try Mounjaro, discuss it with your NHS specialist or private prescriber — they'll advise on timing and dose.
Do I need a prescription for Mounjaro, and where is it dispensed?
Yes, Mounjaro is prescription-only in the UK. On the NHS, it's dispensed through your NHS specialist service. Privately, it's dispensed by a GPhC-registered pharmacy after your online clinical assessment and prescription are issued by a UK-licensed prescriber. Never purchase from unlicensed suppliers.
What happens if Mounjaro isn't available through my NHS service?
If your NHS service doesn't have Mounjaro available, ask about Wegovy (semaglutide) or Saxenda (liraglutide) as alternatives. If NHS access is delayed or unavailable, private prescribing is an option — you pay privately but access the same licensed medication. Some people use private access initially, then transition to NHS if it becomes available later.
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.