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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Monjaro Jab Cost and Access in the UK
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection available in the UK through both NHS specialist services and private online prescribing. The cost varies significantly depending on which route you choose, and eligibility is assessed individually by a licensed prescriber. This guide covers what you need to know about accessing Mounjaro, typical costs, and the clinical assessment process required before treatment begins.
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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 Cost in the UK
Private prescription costs for Mounjaro (tirzepatide) typically range from £129 to £320 per month, depending on the dose and the prescribing service. Starting doses are lower and therefore less expensive; the maximum 15 mg dose is at the higher end of the price range. Each KwikPen contains four weekly injections (one month's supply).
- 2.5 mg starting dose: approximately £129–£150 per month
- 5–10 mg maintenance doses: approximately £180–£250 per month
- 15 mg maximum dose: approximately £280–£320 per month
Private costs do not include the clinical assessment fee, which may be £30–£100 depending on the service. Most private prescribing services are GPhC-registered online pharmacies offering this as a complete package including the consultation, prescription, and medication delivery.
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 to Mounjaro
NHS access: Mounjaro is available through NHS specialist tier 3 and 4 weight management services following referral from your GP. There is no charge at the point of use (covered by prescription charge if eligible). However, NHS waiting lists for specialist services vary significantly by region and can exceed 12 months in many areas.
Private access: Available immediately through an online consultation with a UK-licensed prescriber. No GP referral required. You complete a health assessment, receive a prescription if clinically appropriate, and the medication is dispensed by a GPhC-registered pharmacy. Private treatment is faster but requires payment upfront. Both routes require a genuine clinical assessment before prescription—Mounjaro cannot be obtained without this.
Before starting Mounjaro, your prescriber will assess your BMI, medical history, current medications, and weight-related health conditions. Use our free BMI calculator above to check your personal BMI before your assessment—this helps you understand your starting point. Your prescriber may also recommend our GLP-1 weight loss calculator to help you understand potential outcomes at different doses. If eligible, treatment begins with a 2.5 mg starting dose, with doses gradually increased over weeks if tolerated.
- 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, Mounjaro (tirzepatide) is approved for use within NHS specialist weight management services. Access is through tier 3 or 4 services following GP referral. Availability and waiting times vary significantly by region, with some areas having waiting lists of 6–12+ months. You would need to discuss eligibility with your GP.
How much does Mounjaro cost privately in the UK?
Private Mounjaro typically costs £129–£320 per month depending on dose, plus a consultation fee of £30–£100. Starting doses (2.5 mg) are cheaper; maximum doses (15 mg) are more expensive. Prices vary between GPhC-registered prescribing services, so it's worth comparing.
Do I need a GP referral for private Mounjaro?
No. Private online prescribing services do not require a GP referral. You complete an online health assessment with a UK-licensed prescriber, and if clinically appropriate, you receive a prescription. However, it's helpful to inform your GP that you're considering weight loss treatment so they can monitor your progress.
How long does it take to get Mounjaro privately?
Private services typically process prescriptions within 1–3 working days of completing your online assessment. Medication can usually be delivered within 1–5 working days. NHS access involves waiting for a specialist appointment, which varies by region but can take months.
What happens during a private Mounjaro assessment?
You'll complete a detailed health questionnaire covering your weight, BMI, medical history, current medications, allergies, and any weight-related health conditions like diabetes or high blood pressure. A UK-licensed prescriber reviews your answers and decides if Mounjaro is clinically appropriate for you. If approved, a prescription is issued and sent to a pharmacy for dispensing.
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.