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 for Weight Loss in the UK — Cost & Access
Mounjaro (tirzepatide) is a prescription-only weight loss injection available in the UK through both NHS specialist services and private prescribing routes. If you're considering this weekly weight loss injection for weight management, you'll want to understand how to access it, what it costs, and whether you're eligible. This guide covers everything UK adults need to know about obtaining Mounjaro, comparing the NHS and private routes, and what to expect during the clinical assessment process.
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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 vs Private Access — What Are the Real Differences?
Access to Mounjaro in the UK splits into two distinct routes, each with different timelines, costs, and eligibility processes.
NHS Access: Mounjaro is approved by NICE for use within NHS specialist weight management services (tier 3/4). However, NHS availability varies significantly by region and integrated care board (ICB). Your GP can refer you to your local specialist service, but waiting lists can be substantial — in many areas, patients wait 6–18 months or longer. There is no prescription cost once approved (covered by the NHS), but you cannot choose your dose or timing; these decisions are made by the specialist team. NHS services typically require demonstrated lifestyle attempts and may have strict BMI thresholds depending on your region.
Private Access: Private prescribing offers faster access — often within days or weeks. You complete an online clinical assessment with a UK-licensed prescriber, and if approved, receive a prescription. A GPhC-registered pharmacy then dispenses your Mounjaro. Private costs range from approximately £130–£320 per month depending on your dose and provider. You have choice over prescriber and pharmacy. Private prescribers assess your individual health and medical history but do not typically provide the ongoing lifestyle support that NHS services may offer.
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 Costs, Eligibility, and What the Online Process Involves
Private Mounjaro costs depend on your dose. Starting doses (2.5 mg) are typically £130–£150 monthly; maintenance doses (10–15 mg) range from £200–£320. Eligibility is individually assessed but generally requires a BMI of 27 kg/m² or above, with documented weight-related health conditions, or BMI 30 or above without conditions. The online consultation typically takes 10–15 minutes and asks about your medical history, current medications, and weight goals. If approved, your prescriber issues a prescription valid for 28 days, which you send to a pharmacy. Delivery usually takes 2–5 working days. Use our free GLP-1 weight loss calculator to estimate potential results at different doses, and our BMI calculator to check your starting point before you begin the assessment 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.
Is Mounjaro available on the NHS in the UK?
Yes — NICE has approved tirzepatide (Mounjaro) for NHS use within specialist weight management services. However, availability varies by region, and waiting times can be 6–18 months or longer. Your GP can refer you to your local tier 3 weight management service if you meet local eligibility criteria.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs approximately £130–£150 for starting doses (2.5 mg) and £200–£320 for higher maintenance doses (10–15 mg), depending on your prescriber and pharmacy. Prices vary between providers, so it's worth comparing options before committing.
Do I need a diagnosis to get a private Mounjaro prescription?
No — you do not need a formal diagnosis. A private prescriber will assess your BMI, health history, and any weight-related conditions (like high blood pressure or type 2 diabetes) during an online consultation. If you meet the criteria, they can issue a prescription without a prior diagnosis or GP referral.
What happens during an online Mounjaro consultation?
The consultation is typically a 10–15 minute questionnaire covering your medical history, current medications, allergies, and weight goals. You may be asked about previous weight loss attempts and any health conditions. The prescriber reviews your responses and decides whether Mounjaro is clinically appropriate for you. If approved, you receive a prescription within hours or the next working day.
Can I switch from Mounjaro on the NHS to private prescribing?
Yes — you can switch routes at any time. If you're on an NHS waiting list and prefer faster private access, you can pursue private prescribing independently. If you're already on Mounjaro privately and later gain NHS access, your NHS prescriber will take over your care and dosing schedule. Coordinate with your GP to ensure 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.