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 Slimming Injections — UK Cost and Access Guide
Mounjaro (tirzepatide) is a prescription-only weight management injection available in the UK through both NHS specialist services and private online prescribing. Costs and access routes vary significantly depending on which pathway you choose. This guide explains NHS eligibility, private pricing, how the online consultation process works, and what to expect when accessing this medication. Understanding your options helps you make an informed decision about whether Mounjaro is right for you.
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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.
Private Mounjaro Cost and Access in the UK
Private prescription costs for Mounjaro typically range from £129 to £320 per month, depending on your dose and the prescribing provider. The actual price you pay varies based on several factors: the dose you're prescribed (doses range from 2.5 mg up to the maximum 15 mg weekly), how many pens are in each supply, and individual provider pricing structures.
To access Mounjaro privately, you complete an online health consultation with a UK-licensed prescriber. This assessment usually covers your medical history, current medications, BMI, and weight-related health conditions. If approved, a prescription is issued and dispensed by a GPhC-registered online pharmacy. The process typically takes 24–48 hours from consultation to receiving your KwikPen. You'll also receive guidance on injection technique, storage (refrigerated at 2–8°C), and what side effects to monitor. Many people choose the private route because it avoids NHS waiting lists, which can extend months or years in some regions.
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 vs Private Access — Which Route is Right for You?
NHS access is free but requires specialist referral and assessment. Your GP must refer you to a tier 3 specialist weight management service in your area. From there, a multidisciplinary team (dietitian, nurse, doctor) assesses your eligibility based on BMI and weight-related health conditions. NHS availability varies dramatically by region—some integrated care boards (ICBs) have established Mounjaro programmes, whilst others have waiting lists of 12+ months or very limited capacity. Once approved, NHS prescriptions are free under the prescription charge scheme.
Private access is faster but you pay directly. Online consultations happen within days, prescriptions are issued quickly, and you begin treatment within 1–2 weeks. This suits people who want to start treatment sooner or whose NHS region has limited availability. Your GP can still monitor you during treatment, even if prescribed privately.
Use our GLP-1 weight loss calculator to estimate potential weight loss outcomes at different Mounjaro doses, and our BMI calculator to confirm whether you meet the eligibility thresholds (BMI ≥30, or ≥27 with weight-related health conditions).
- 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 much does Mounjaro cost per month in the UK privately?
Private Mounjaro costs typically range from £129 to £320 per month, depending on your prescribed dose (2.5 mg to 15 mg weekly) and the provider's pricing. Doses escalate over 16–20 weeks, so your initial costs may be lower than maintenance costs. Always check the specific provider's pricing before starting treatment.
Can I get Mounjaro on the NHS in the UK?
Yes, Mounjaro is now approved on the NHS through NICE for adults with a BMI of 30+ or 27+ with weight-related health conditions. Access is via tier 3 specialist weight management services. You'll need a GP referral. NHS availability and waiting times vary significantly by region—some areas have established programmes whilst others have limited capacity or long waiting lists.
What's the difference between Mounjaro and Wegovy cost in the UK?
Both are typically available privately at similar price ranges (£129–£320/month depending on dose). Mounjaro uses doses from 2.5 mg to 15 mg weekly, whilst Wegovy uses lower doses (0.25 mg to 2.4 mg weekly). Private costs depend more on your specific dose and provider than on which medication. NHS coverage also varies by region for both.
How long does the online consultation process take?
Most online consultations take 15–30 minutes. The prescriber will ask about your medical history, current medications, BMI, and weight-related conditions. If approved, you'll receive a prescription within 24–48 hours and your first KwikPen within 1–2 weeks. Some providers offer same-day consultations, though appointments may need to be booked in advance.
Do I need a GP referral to get Mounjaro privately?
No, you do not need a GP referral for private prescription. You can book an online consultation directly with any registered private prescriber. However, it's recommended to inform your GP that you're starting Mounjaro so they can monitor your health and adjust other medications if needed. Your GP can provide continuity of care.
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.