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 Doses in the UK — Cost and Access Guide
Mounjaro (tirzepatide) is available in the UK as a once-weekly injection for adults with obesity or overweight with weight-related health conditions. The medication comes in doses ranging from 2.5 mg to 15 mg, with costs and access varying significantly depending on whether you're accessing it through the NHS or privately. Understanding your options, how much it costs, and the prescribing pathway can help you make an informed decision about whether Mounjaro is right for you.
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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 Cost in the UK
In the UK private sector, Mounjaro is available through online prescription services following a clinical assessment with a UK-licensed prescriber. Private costs typically range from £129 to £320 per month depending on your dose and the provider, with each KwikPen containing four weeks' worth of injections. The starting dose of 2.5 mg is usually the most affordable, while higher maintenance doses (10 mg to 15 mg) cost more. When budgeting, remember you'll likely need to start at 2.5 mg and increase weekly over 16–20 weeks to reach your target dose, so initial monthly costs will be lower than long-term maintenance costs. Private prescribing services assess your medical history, current medications, weight, and BMI using our GLP-1 weight loss calculator equivalent to help determine suitability before issuing a prescription. Payment is usually required upfront, and pens are dispatched by registered pharmacies. There is no waiting list on the private route, making it faster than NHS access for many people.
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 Access vs Private — Which Route is Right for You?
NHS access: Mounjaro is now approved by NICE for use within specialist tier 3 and tier 4 weight management services across the UK, but availability remains patchy and waiting lists are significant in many regions — sometimes 12–24 months. Your GP refers you to your local integrated care board's (ICB) weight management service; assessment and prescription happen at tier 3 level if eligible. There is no cost to you on the NHS. Private access: Faster (typically 24–48 hours from consultation to prescription), no waiting list, but you pay out of pocket. The online consultation process takes 15–20 minutes, includes health questions and sometimes a video call with the prescriber, and results in a prescription if you meet clinical criteria. Private prescribers assess the same NHS eligibility thresholds (BMI ≥30, or BMI 27–29.9 with weight-related health conditions like type 2 diabetes or hypertension), though regional variation in access means some people can't access either route quickly.
- 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 in the UK on the NHS?
Mounjaro is free on the NHS if prescribed through a specialist weight management service. However, NHS access requires a GP referral to tier 3/tier 4 services and can involve lengthy waiting lists (6–24 months depending on your region). Ask your GP about local availability in your integrated care board area.
What's the cheapest Mounjaro dose available privately?
The starting dose of 2.5 mg is typically the cheapest, around £129–£160 per month. However, most people titrate up to 5 mg, 10 mg, or 15 mg over 16–20 weeks, so maintenance doses (10–15 mg) cost £250–£320 per month. Budget accordingly for the full treatment course.
How do I get a private Mounjaro prescription in the UK?
Register with a private online prescribing service, complete a health questionnaire and consultation (usually 15–20 minutes), and the prescriber will assess your eligibility based on BMI and health conditions. If approved, a prescription is issued to a registered pharmacy and your KwikPen is dispatched. The whole process typically takes 24–48 hours.
Can I switch from private Mounjaro to NHS Mounjaro?
Yes, you may be able to transfer to NHS provision if you're approved by your local specialist weight management service and your region funds it. Discuss this with your GP or your private prescriber — you may need to pause private treatment while awaiting NHS assessment, depending on your local pathway.
Does tirzepatide (Mounjaro) cost more or less than Wegovy on the NHS?
Both Mounjaro and Wegovy are available through NHS specialist services at no cost to you. On the private market, costs are similar — both typically range from £129–£320 per month depending on dose. Individual pricing varies by pharmacy. Use our BMI calculator to check your eligibility for either medication.
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.