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
Cheapest Mounjaro Injection in the UK — What to Know
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private online prescribing, with costs varying significantly depending on your route of access and starting dose. Understanding the true cost — including dose escalation — helps you make an informed decision about whether this weekly weight loss injection is right for your budget and health needs.
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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.
How Much Does Mounjaro Cost in the UK?
NHS access: Mounjaro prescribed through NHS specialist tier 3 weight management services is free at the point of delivery if eligible, though availability varies significantly across regions and waiting lists can extend many months.
Private access pricing (approximate):
- Starting dose (2.5 mg): £129–£180 per 4-week supply (KwikPen)
- 5 mg dose: £145–£200 per month
- 10 mg dose: £180–£240 per month
- 15 mg dose (maximum): £220–£320 per month
Monthly costs reflect individual prescriber and pharmacy pricing — always confirm the exact price for your dose before committing. Some private providers offer discount packages for 3 or 6-month supplies. Each KwikPen contains 4 weekly injections, so costs shown reflect one month's supply.
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.
Finding the Most Affordable Mounjaro Option
To access the cheapest Mounjaro option, check NHS eligibility first through your GP — free treatment beats any private cost if you qualify and can access a specialist service. If NHS waiting times are prohibitive, compare private prescribers: prices vary by dose, provider, and whether you commit to multiple months upfront. Use our GLP-1 weight loss calculator to understand your projected dose progression, which helps you estimate total costs over 3–6 months. Always verify you're buying from a GPhC-registered pharmacy with a UK-licensed prescriber — cheaper listings from unregistered sources carry serious safety and legal risks.
Additional costs to consider: GP appointments for medical history (may be free on NHS or £50–150 privately), blood tests if required (usually included in private assessment), and potential travel to collect injections. Some weight loss programmes bundle Mounjaro with dietary support or progress tracking — these often cost more upfront but may offer better value if you need structured support alongside the medication itself.
- 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 NHS Mounjaro free?
Yes, Mounjaro prescribed through NHS specialist weight management services is free to patients. However, NHS eligibility requires a BMI of 30+ (or 27+ with weight-related health conditions), and access is through specialist tier 3 services — not standard GP prescription. Waiting times vary by region from weeks to over a year.
What's the cheapest private Mounjaro dose to start?
The starting dose (2.5 mg) typically costs £129–£180 per month privately. However, most people escalate to 5 mg or higher within 4–8 weeks, so budget for dose increases. Confirm exact pricing with your chosen prescriber before starting treatment.
Why does Mounjaro cost more than Wegovy?
Mounjaro and Wegovy have similar pricing in the UK (both £129–£320 per month depending on dose). Mounjaro may cost slightly more at higher doses due to its dual GIP+GLP-1 mechanism, but prices vary between providers. Compare directly with your prescriber.
Are there Mounjaro discount programmes in the UK?
Some private prescribers offer discounts for 3 or 6-month upfront payment. A few weight management clinics include Mounjaro within broader treatment packages. Always ask about available discounts, but avoid suspiciously cheap offers from unregistered sources.
Can I get cheaper Mounjaro by switching doses or taking breaks?
Stopping and starting Mounjaro is not recommended — it disrupts appetite regulation benefits and may increase side effects on restart. Dose reduction (not stopping) may be appropriate if side effects are severe, but this decision requires prescriber guidance. Cost-cutting by skipping doses is unsafe.
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.