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 2.5mg Weight Loss: Cost and Access in the UK
Mounjaro 2.5mg is the starting dose of tirzepatide, a prescription-only weekly weight loss injection available in the UK through both NHS specialist services and private prescription routes. The cost and access pathway depend on which route you choose. This guide explains UK pricing, how to access Mounjaro privately, NHS eligibility, and what to expect from the application process. You can use our free BMI calculator to check if you meet the eligibility criteria for prescription weight loss treatment, and our GLP-1 weight loss calculator to estimate potential outcomes.
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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.
Private Mounjaro Access and UK Cost Context
In the UK, private Mounjaro prescriptions are available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. The 2.5mg starting dose typically costs between £129 and £180 per month depending on the provider, though this varies. Each KwikPen contains 4 doses (4 weeks' supply), and you'll remain on 2.5mg for the first 4 weeks before dose titration. As a weekly weight loss injection, Mounjaro requires ongoing prescription repeats — you cannot simply buy a single dose. Private access does not require NHS referral, making it faster than the NHS route in most regions. However, private prescriptions are not covered by NHS prescriptions, so you pay the full cost. Some providers offer subscription models or bulk discounts for multiple months upfront.
- Typical private cost: £129–£180 per month for 2.5mg
- Each pen contains 4 weekly injections
- Prescription issued after online clinical assessment
- Dispensed by verified UK pharmacy
- Payment required before dispatch
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 Routes in the UK
The NHS route requires referral to a tier 3 specialist weight management service, typically through your GP. NICE has approved tirzepatide (Mounjaro) for specialist NHS services, but availability varies significantly by region and ICB funding. NHS waiting lists for specialist weight management can be several months to over a year in many areas. Once approved by an NHS specialist, Mounjaro is free on prescription. The private route is faster — you book an online consultation, complete a health questionnaire, and if approved by the prescriber, receive your prescription within 24–48 hours. Private prescriptions do not require GP involvement. Both routes require a clinical assessment to confirm you meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions).
- NHS: free on prescription, longer wait, requires GP referral
- Private: paid upfront, faster access, no NHS referral needed
- Both require clinical eligibility assessment
- Both are prescription-only medicines
- 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 2.5mg cost on the NHS in the UK?
Mounjaro is free on prescription once prescribed by an NHS specialist weight management service. However, access requires GP referral and specialist assessment, and waiting times vary from months to over a year depending on your region. NICE has approved tirzepatide for NHS use, but local availability depends on your ICB funding and service capacity.
Can I get Mounjaro 2.5mg privately without seeing my GP?
Yes. Private Mounjaro prescriptions are available through GPhC-registered online pharmacies without NHS referral. You'll complete an online consultation with a UK-licensed prescriber, who will assess your eligibility based on your BMI and health history. If approved, you receive a prescription and the pharmacy dispenses your KwikPen.
What's included in the monthly cost of private Mounjaro?
The monthly cost (typically £129–£180) covers the KwikPen containing 4 weekly 2.5mg doses, dispensing fees, and the prescriber consultation. It does not include GP oversight or ongoing medical monitoring. Some providers include follow-up consultations; others charge separately. Check the provider's full terms before purchasing.
How long do I stay on the 2.5mg dose before increasing?
Mounjaro dose titration requires a minimum of 4 weeks on each dose. You'll use the 2.5mg KwikPen (4 injections) for the first 4 weeks, then move to 5mg for weeks 5–8, and so on. Your prescriber will guide the titration schedule based on your response and tolerance.
Is private Mounjaro cheaper than NHS after the waiting time?
No. Private Mounjaro costs £129–£180 monthly indefinitely, while NHS prescriptions are free once approved. However, private access is significantly faster — typically days rather than months or years. Many people choose private to avoid NHS waiting lists, accepting the cost for quicker access.
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.