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 Will Mounjaro Cost in 2025?
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or private prescription in the UK. In 2025, private prescription costs typically range from £129 to £320 per month, depending on your dose and the prescribing service. NHS access is free at the point of use but depends on referral to specialist weight management services and varies by region. Understanding your options helps you plan the financial commitment involved in this weight management treatment.
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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.
Private Prescription Costs for Mounjaro in 2025
Private prescription costs in 2025 vary based on the dose you're prescribed. Mounjaro is available through UK-licensed online prescription services, with typical pricing:
- Lower doses (2.5–5 mg): approximately £129–£149 per month
- Mid-range doses (7.5–10 mg): approximately £169–£199 per month
- Higher doses (12.5–15 mg): approximately £239–£320 per month
Each KwikPen contains 4 weeks of doses. Prices may include the online consultation fee (typically £20–£50) and are charged per prescription issued. Tirzepatide costs depend on your starting dose and whether you need dose escalation — most people begin at 2.5 mg and increase every 4 weeks. Costs do not include GP monitoring if required. Always confirm current pricing with the prescribing service, as prices can vary and change throughout the year.
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 vs Private Access — What Affects Cost?
NHS access is free but requires referral to a tier 3 specialist weight management service. Eligibility criteria include a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or hypertension. However, NHS availability varies significantly by region and waiting lists can extend months or years in many areas. Private prescription offers faster access without NHS referral — you can begin an online consultation within days. The trade-off is cost: private treatment costs £129–£320 monthly depending on dose. Your total cost also depends on how long you take Mounjaro (it's typically used for 6–12 months or longer) and whether you need dose adjustments. Use our GLP-1 weight loss calculator to estimate potential outcomes, helping you decide if the investment aligns with your weight loss goals.
- 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.
What's included in the monthly cost of private Mounjaro?
The monthly cost typically covers the KwikPen prescription (4 weeks of doses) and sometimes the online consultation fee. Costs do not usually include GP monitoring, blood tests, or follow-up consultations — confirm what's included when arranging your prescription.
Why do Mounjaro prices vary so much between doses?
Higher-dose pens (12.5 mg and 15 mg) contain more active medication, so manufacturing and supply costs are higher. You'll typically start at 2.5 mg and escalate every 4 weeks, so your monthly cost will increase as your dose increases.
Can I get Mounjaro cheaper on the NHS in 2025?
Yes, NHS access is free at the point of use, but you must be referred to a specialist tier 3 weight management service by your GP and meet eligibility criteria. NHS availability depends on your region (ICB) and waiting lists vary considerably.
Does the KwikPen cost change if I need to stay on Mounjaro longer?
No, the cost per month remains the same at your current dose. However, if you escalate to a higher dose, your monthly cost will increase accordingly. The total cost depends on how long you take the medication.
How does Mounjaro cost compare to Wegovy in 2025?
Both medications have similar private pricing (£129–£320 monthly), though specific costs vary by prescribing service and dose. Mounjaro is a dual GIP/GLP-1 agonist starting at 2.5 mg, while Wegovy (semaglutide) starts at 0.25 mg — the dose ranges differ, which affects pricing structures slightly.
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.