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 Jabs — Cost and Access in the UK
Mounjaro (tirzepatide) slimming jabs are available in the UK through both NHS specialist services and private prescription routes, though costs and access timelines differ significantly. This guide explains how to access Mounjaro, what you can expect to pay, and the differences between NHS and private options so you can make an informed decision about whether this prescription-only weight management injection is right for you.
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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 and Access in the UK
Private prescription is the quickest route to access Mounjaro in the UK. Private providers typically charge between £129 and £320 per month depending on your dose, with costs increasing as you escalate through the dose titration schedule (starting at 2.5 mg and titrating up to 15 mg over several months). Each KwikPen contains four weekly injections, so one pen covers one month of treatment. Online consultations with a UK-licensed prescriber usually cost £30 to £75 and must be completed before a prescription is issued. Once approved, your prescription is dispensed by a GPhC-registered pharmacy. Private access avoids NHS waiting lists — you can typically start treatment within 1–2 weeks of your first consultation. However, this route is entirely self-funded and not subsidised by the NHS, making it significantly more expensive than NHS access for long-term use. Use our GLP-1 weight loss calculator to estimate your projected weight loss at different doses before committing to treatment.
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
NHS route: Mounjaro is approved by NICE for use within NHS tier 3 specialist weight management services. To access it, you'll need a referral from your GP to your local integrated care board (ICB) specialist service. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or cardiovascular disease. The major limitation is availability and waiting times — many areas have significant waiting lists (sometimes 6–18 months), and not all regions currently offer tirzepatide. Cost to you is free once prescribed, but access depends entirely on your local NHS provision.
Private route: Faster access without NHS referral. You complete an online clinical assessment with a UK-licensed prescriber, who decides if Mounjaro is suitable based on your health profile. If approved, you pay privately for both the prescription and medication. This suits those who cannot wait for NHS services or prefer immediate access.
- 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?
Private costs typically range from £129 to £320 per month depending on your dose. Costs are highest at the maximum 15 mg dose. Each dose increase during titration may increase your monthly cost. Online consultation fees (usually £30–75) are separate from medication costs. NHS prescription is free, but access requires referral to a specialist service.
Can I get Mounjaro on the NHS in the UK?
Yes — NICE has approved tirzepatide for NHS use through tier 3 specialist weight management services. However, availability varies significantly by region. You'll need a GP referral and must meet eligibility criteria (BMI ≥30, or ≥27.5 with weight-related health conditions). Waiting lists in many areas are very long — sometimes 6–18 months.
What's the difference between Mounjaro and Wegovy in terms of cost?
Both are expensive on the private route (typically £129–£320/month depending on dose), though exact costs vary by provider and dose. Mounjaro titrates to a higher maximum dose (15 mg) compared to Wegovy (2.4 mg), which may affect long-term costs. Clinical trial data suggests Mounjaro may achieve slightly greater average weight loss, but individual results vary significantly.
How do I access Mounjaro privately in the UK?
Complete an online consultation with a UK-licensed prescriber. You'll be asked about your medical history, current medications, weight, height, and health conditions. If the prescriber assesses you as suitable, they'll issue a prescription, which is then dispensed by a GPhC-registered pharmacy. The entire process typically takes 1–2 weeks from consultation to receiving your first pen.
Do I need to be weighed and measured before starting Mounjaro?
Yes — any licensed prescriber will need your current weight and height to calculate your BMI and assess eligibility. Private consultations include this assessment online. On the NHS route, the specialist service will conduct full health checks including weight, blood pressure, and blood tests before prescribing. Both routes require confirmation that you meet clinical eligibility criteria.
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.