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 12.5mg Mounjaro Cost in the UK?
The cost of 12.5mg Mounjaro varies significantly depending on whether you access it through the NHS or privately. On the NHS, Mounjaro may be available free through specialist weight management services if you meet eligibility criteria—though access is often limited and waiting times can be lengthy. Privately, 12.5mg Mounjaro typically costs between £150–£280 per month depending on your provider. This is the maximum tirzepatide dose; most people start at lower doses and increase gradually over several weeks through the dose titration schedule.
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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.
NHS vs Private Access for Mounjaro 12.5mg
NHS access: Mounjaro (tirzepatide) is approved for use within NHS specialist tier 3/4 weight management services. However, availability varies dramatically by region and ICB. Many areas have extremely long waiting lists—sometimes 12–24 months. You must be referred by your GP to a specialist service. Eligibility requires a BMI of 30 or above (or 27+ with weight-related health conditions). Free if approved, but access is not assured.
Private access: Available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. Costs typically range £150–£280/month for 12.5mg, depending on pharmacy and provider fees. No waiting list. You can start within days if clinically suitable. Use our free BMI calculator above to check whether you might meet eligibility criteria before consulting a prescriber.
- NHS = free but limited availability and long waits
- Private = faster access but out-of-pocket cost
- Both require prescription from a 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.
Understanding Mounjaro Dose Titration and Cost
12.5mg is the maximum dose of tirzepatide. Most people do not start here. The standard dose titration begins at 2.5mg per week for weeks 1–4, then increases by 2.5mg every 4 weeks: 5mg, 7.5mg, 10mg, 12.5mg, and finally 15mg (the absolute maximum). Reaching 12.5mg typically takes 16–20 weeks. Each KwikPen contains 4 weekly doses. If you're comparing Mounjaro costs, remember you'll likely spend several months at lower doses before reaching 12.5mg. Our GLP-1 weight loss calculator can help you estimate potential costs and outcomes at different doses.
Individual results vary—some people reach their target weight at lower doses and choose to maintain there rather than escalating further.
NHS Weight Loss: Do You Qualify?- 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 12.5mg Mounjaro cheaper on the NHS or private?
On the NHS, it's free if you meet eligibility criteria and can access a specialist service—but availability is very limited and waiting times can exceed 12 months. Privately, 12.5mg costs £150–£280/month. For many people, private access is faster despite the cost. Check your local NHS weight management services first, then consider private options if waiting times are too long.
Can I get 12.5mg Mounjaro without waiting for NHS specialist services?
Yes. Private online prescribing services can assess you and issue a prescription within days if clinically suitable. You'll pay privately (typically £150–£280/month), but there's no waiting list. Both routes require a clinical assessment—you cannot simply buy Mounjaro without a prescription.
Why does Mounjaro cost more at higher doses?
Higher doses contain more active tirzepatide per pen, so pharmaceutical and supply costs are higher. A 12.5mg pen costs more than a 5mg pen. However, the price difference is usually modest—typically £20–40/month between dose levels depending on your provider.
Is Mounjaro vs Wegovy cheaper? Which costs less?
Pricing for Mounjaro and Wegovy is similar among UK private providers—usually £150–£280/month depending on dose and provider. Mounjaro's maximum dose (15mg) is higher than Wegovy's (2.4mg), so if you're comparing at equivalent therapeutic doses, costs are nearly identical. Clinical trial data showed tirzepatide may produce slightly greater weight loss on average, but individual results vary significantly.
What's included in the Mounjaro cost? Are there hidden fees?
Private provider costs typically include the KwikPen, clinical assessment, and prescription. Some providers charge separately for follow-up consultations (usually £25–60 per appointment). Always confirm the total cost upfront, including any follow-up fees. The NHS cost is zero if you qualify, but includes NHS specialist clinic time and monitoring.
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.