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 Does Mounjaro Cost in the UK?
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. Through NHS specialist weight management services, Mounjaro is typically free at the point of use if you meet eligibility criteria — though accessing it can involve waiting lists of several months to over a year in many regions. Private prescriptions cost between £150 and £320 per month depending on your dose and the provider. Understanding both routes can help you decide the best option for your circumstances.
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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.
Mounjaro Pricing — NHS vs Private Routes
NHS access: Mounjaro (tirzepatide) is provided free through NHS specialist tier 3 and tier 4 weight management services if you meet NICE guidance eligibility criteria. You must have a BMI of 30 kg/m² or above, or BMI of 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. However, NHS access requires a referral from your GP to specialist services, and waiting times vary dramatically by region — some areas have waiting lists of 12–24 months. Contact your local Integrated Care Board (ICB) to check availability in your area.
- No prescription cost: Free once prescribed through NHS
- Clinic visits: Usually free with NHS prescribing
- Waiting times: Variable by region, typically 6–24 months
- Eligibility assessment: Conducted by specialist NHS team
Private access: Private UK prescribers charge for online consultations (typically £25–£50) plus the medication cost. A KwikPen containing 4 weeks of injections costs between £150 and £320 depending on dose — lower doses cost less, highest dose (15 mg) typically most expensive. Some private providers offer subscription models with discounted rates for longer-term use.
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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.
Understanding Dose Titration and Long-Term Costs
Mounjaro treatment involves gradual dose increases every 4 weeks, starting at 2.5 mg and potentially reaching 15 mg maximum. Initial months cost less because you're on lower doses — costs rise as you titrate up. Most people spend 16–20 weeks titrating to their target dose. If considering private access, calculate 12-month costs by estimating your likely dose trajectory. Use our free GLP-1 weight loss calculator to project your potential weight loss at different doses — this can help determine whether the investment aligns with your health goals. Compare this with the cost and waiting time of NHS access in your region to make an informed decision.
- 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 a Mounjaro KwikPen cost privately in the UK?
A KwikPen (4-week supply) costs between £150–£320 depending on dose. The 2.5 mg starter dose is typically cheaper (~£150), while the 15 mg maximum dose is most expensive (~£320). Costs rise as you titrate to higher doses over 16–20 weeks. Some private providers offer subscription discounts for longer-term commitments.
Is Mounjaro free on the NHS in the UK?
Yes, Mounjaro is free on the NHS if prescribed through specialist tier 3 or tier 4 weight management services and you meet NICE eligibility criteria (BMI 30+, or 27–29.9 with weight-related health conditions). However, NHS availability is limited and waiting times range from 6–24 months depending on your region. Contact your local ICB to check local availability.
How do I access Mounjaro on the NHS?
Ask your GP for a referral to your local NHS specialist weight management service (tier 3). Your GP will assess whether you meet criteria and refer you. You'll then undergo assessment by the specialist team before being offered Mounjaro. Waiting times vary by region — some areas have 12–24 month waits. Private access via an online prescriber is faster but involves prescription costs.
What's the total cost of a year of Mounjaro privately?
Rough estimate: £1,800–£3,200 for 12 months, depending on your dose progression. If starting at 2.5 mg (£150) and titrating to 10 mg (£250) over 16 weeks, then remaining on 10 mg, your annual cost is approximately £2,500–£2,800. Always ask your private provider for a full cost breakdown for your expected treatment plan.
Can I switch from private Mounjaro to NHS Mounjaro?
Potentially, but it's not straightforward. If you start privately and later become eligible for NHS access, you would need to apply through your GP for an NHS referral and meet the service's criteria. You cannot simply "transfer" — you'd pause private treatment and wait for NHS assessment. Some regions allow bridging, so ask your GP about local policy if this interests you.
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.