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
Free tracker included with every download this week
How Much Do Mounjaro Injections Cost in the UK?
Mounjaro (tirzepatide) injection costs in the UK depend on whether you access it through the NHS or privately. NHS prescriptions may be free at the point of care if eligible through specialist weight management services, though access varies significantly by region. Private costs typically range from £150 to £350 per month depending on dose, with each KwikPen containing four weekly injections. Pricing differences reflect supply, demand, and individual pharmacy variations across the UK.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Mounjaro Costs: NHS vs Private Access in the UK
NHS Access: Mounjaro is available through the NHS for eligible adults, but access is limited to specialist tier 3 weight management services. Prescription costs are typically free under the NHS prescription fee system (or the standard £9.90 charge in England if applicable). However, availability varies dramatically by region and integrated care boards (ICBs). Many areas have significant waiting lists — sometimes 6–18 months — and not all ICBs currently fund tirzepatide. Your GP can refer you to your local specialist service, but eligibility and waiting times depend on your location.
Private Access: Private prescriptions cost between £150–£350 per month depending on dose. Each KwikPen contains 4 weekly injections, so a monthly supply lasts exactly 4 weeks. Starting doses (2.5 mg) are typically cheaper than maximum doses (15 mg). Prices vary across different GPhC-registered online pharmacies and private weight management clinics. Private access does not require NHS referral — only an online clinical assessment with a UK-licensed prescriber.
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.
What Affects Mounjaro Pricing and Availability?
Several factors influence Mounjaro costs: dose level (starting 2.5 mg is less expensive than 15 mg maintenance doses), supply chain and pharmacy overheads, regional NHS funding decisions, and private provider competition. The tirzepatide KwikPen is a pre-filled, single-use device with four doses — you cannot split or reuse pens. Some private providers offer subscription discounts for ongoing treatment, which may reduce per-month costs. NHS waiting lists and regional availability mean private access is often quicker, though at a cost. Use our free GLP-1 weight loss calculator to estimate potential results at different doses before committing to treatment. Your prescriber can discuss payment options and whether treatment duration affects overall cost.
- 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 free on the NHS in the UK?
Mounjaro is available on the NHS through specialist weight management services, but only for eligible adults. Prescriptions are typically free under the NHS prescription fee system. However, access varies significantly by region — some areas have long waiting lists or limited funding. Your GP can refer you to local services, but availability depends on your integrated care board (ICB).
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs range from £150–£350 per month depending on dose. A single KwikPen contains 4 weekly injections (one month's supply). Starting doses (2.5 mg) are typically cheaper than maximum doses (15 mg). Some online pharmacies offer subscription discounts. Prices vary across providers.
Is Mounjaro more expensive than Wegovy in the UK?
Pricing is broadly similar — both typically cost £150–£350 per month privately. However, costs vary by pharmacy, dose, and region. Mounjaro and Wegovy work differently (tirzepatide is a dual GIP+GLP-1 agonist, whilst Wegovy is GLP-1 only), so choice should be based on clinical suitability, not price alone. Discuss options with your prescriber.
What is included in Mounjaro KwikPen costs?
A Mounjaro KwikPen contains 4 pre-filled weekly injections of a single dose strength. Costs cover the device and medication only — not consultations, blood tests, or follow-up appointments. These may be charged separately by private providers. NHS specialist services cover consultations and monitoring as part of the pathway.
Can I get a cheaper Mounjaro dose to save money?
You should not choose a lower dose for cost reasons — doses are determined by clinical assessment and individual response. Doses are escalated gradually from 2.5 mg to a maintenance level (typically 10–15 mg) over 16+ weeks. Prescribers will assess the right dose for you. Use our free BMI calculator to understand your starting health context before your consultation.
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.