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
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Where to Get the Cheapest Mounjaro in the UK
If you're looking for the cheapest place to get Mounjaro in the UK, you have two main routes: NHS specialist services or private online prescribing. Costs vary significantly depending on which route you choose, your starting dose, and where you access treatment. This guide compares both options so you can understand the actual cost differences between Mounjaro and Wegovy, and what affects the price you'll pay for your weight loss injection treatment.
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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 Mounjaro Costs in the UK
NHS access is free at the point of use if you're prescribed Mounjaro through an NHS specialist weight management service — however, availability varies dramatically by region, and waiting lists can be months or even years in many areas. NICE has approved tirzepatide (Mounjaro) for use within NHS tier 3 and 4 weight management services, but referral from your GP and acceptance by your local integrated care board (ICB) are required.
Private prescribing typically costs between £129 and £320 per month depending on your dose. A 2.5mg starting dose is usually cheaper than higher maintenance doses like 10mg or 15mg. Our free GLP-1 weight loss calculator can help you estimate potential costs at different dose levels. Private providers include GPhC-registered online pharmacies following a clinical assessment by a UK-licensed prescriber. You don't need an NHS referral for private access.
- 2.5mg (starting dose): usually £130–£160/month
- 5–7.5mg (early escalation): usually £160–£200/month
- 10–15mg (maintenance doses): usually £220–£320/month
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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.
How Mounjaro and Wegovy Compare on Cost and Effectiveness
Wegovy (semaglutide) is often similarly priced to Mounjaro in private prescribing, typically ranging from £129 to £280 per month depending on your dose and provider. Clinical trial data from SURMOUNT showed Mounjaro achieved average weight loss of 15–21% of body weight, while Wegovy's STEP trials showed approximately 15% average weight loss — though individual results vary significantly and depend on diet, activity level, and personal factors. Both are prescription-only medicines requiring clinical assessment, and both work through similar mechanisms (though Mounjaro is a dual GIP+GLP-1 agonist while Wegovy is GLP-1 only). Your prescriber will advise which suits you better based on your health profile.
- 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.
Can I get Mounjaro on the NHS for free?
Yes, if you're accepted by an NHS specialist weight management service and meet eligibility criteria (BMI 30+ or 27+ with weight-related health conditions). However, NHS availability is very limited and waiting lists can be lengthy. Ask your GP about referral to your local tier 3 service, but be prepared for a long wait.
Why is private Mounjaro more expensive at higher doses?
Each dose strength requires a separate KwikPen, and higher-dose pens cost more to manufacture and supply. Starting doses like 2.5mg are cheaper than maintenance doses like 15mg. Costs also reflect the prescriber assessment and pharmacy dispensing fees.
Is Mounjaro cheaper than Wegovy?
Prices are usually comparable in private prescribing, typically £129–£320/month for either medication depending on dose and provider. Your prescriber will assess which is more suitable for your health, not which is cheapest. Individual results vary significantly.
What does the starting Mounjaro dose cost?
A 2.5mg starting dose typically costs around £130–£160 per month privately. You'll stay on this dose for 4 weeks before escalating. Prices vary between providers, so it's worth comparing GPhC-registered pharmacies.
How do I access the cheapest option — NHS or private?
NHS is free but has long waits and regional availability issues. Private costs £130–£320/month depending on dose but offers faster access without referral. Use our GLP-1 weight loss calculator to estimate projected outcomes and costs at different doses to help you decide.
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.