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 2.5mg Cost in the UK?
The cost of Mounjaro 2.5mg varies significantly depending on whether you access it through the NHS or via private prescription. The 2.5mg starting dose is the initial adjustment dose used for the first four weeks of tirzepatide treatment. NHS access to Mounjaro is limited and region-dependent, typically available through specialist tier 3 weight management services with potentially long waiting lists. Private prescription costs are more accessible and immediate, though prices vary by provider. Understanding your options and eligibility can help you plan your weight management journey effectively.
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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 2.5mg Cost: NHS vs Private Access
NHS Mounjaro access: Mounjaro (tirzepatide) is approved by NICE for use within specialist NHS weight management services, but availability is extremely limited and varies significantly by region and integrated care board (ICB). Most patients face waiting lists of many months or years. If available in your area, the medication itself would be free, though accessing it requires referral to tier 3 services and meeting strict eligibility criteria: BMI of 30 or above (or 27 with weight-related health conditions like type 2 diabetes).
Private prescription costs: Through private online prescribers and GPhC-registered pharmacies, Mounjaro 2.5mg typically costs between £129 and £200 per month depending on the provider. The 2.5mg KwikPen contains 4 weekly injections (one month supply). Private access is faster and does not require NHS referral, requiring only an online clinical assessment from a UK-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.
Dose Titration and Long-Term Cost Considerations
The 2.5mg dose is rarely a maintenance dose — most patients escalate every 4 weeks to 5mg, 7.5mg, 10mg, 12.5mg, or 15mg based on clinical response. Each dose escalation typically increases monthly cost slightly. Over 12 months, private patients may spend £1,500–£3,000 depending on final maintenance dose and provider pricing. Our GLP-1 weight loss calculator can help you estimate potential outcomes and costs at different doses. Always compare prices between providers, as costs vary significantly, and confirm that prescribers are UK-licensed and the pharmacy is GPhC-registered.
- 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 Mounjaro 2.5mg available on the NHS?
Mounjaro is NICE-approved for NHS specialist weight management services, but availability is extremely limited and region-dependent. Most areas have long waiting lists of 6–24+ months. Private prescription is often faster, though costs apply. Contact your GP to check NHS availability in your region.
How much does a Mounjaro 2.5mg KwikPen cost privately?
A single 2.5mg KwikPen (4-week supply) typically costs £129–£200 privately, depending on the provider. Prices vary between online prescribers and pharmacies. Always confirm costs before starting, and check that your prescriber is UK-licensed and the pharmacy is GPhC-registered.
Why is 2.5mg only a starting dose?
The 2.5mg dose is designed to allow your body to adjust to tirzepatide and assess tolerability. After 4 weeks on 2.5mg, prescribers typically increase the dose. Most patients escalate through 5mg, 7.5mg, 10mg, 12.5mg to reach 15mg (maximum dose) based on how well they respond.
Does Mounjaro 2.5mg cost less than higher doses?
Yes, 2.5mg is the lowest dose and typically the least expensive. However, you'll only use this dose for the first month. As you escalate to higher maintenance doses, monthly costs increase. Our GLP-1 weight loss calculator can help estimate ongoing costs at different doses.
What should I check before paying for Mounjaro privately?
Verify the prescriber is UK-licensed, the pharmacy is GPhC-registered, and confirm the exact price before purchase. Check whether the cost includes the prescription fee and any follow-up consultations. Compare prices between providers — costs vary significantly. Always request a legitimate prescription rather than purchasing without clinical assessment.
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.