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
Where to Find the Cheapest Mounjaro Injection in the UK
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. The NHS offers free treatment through specialist weight management services, but waiting lists can be lengthy. Private prescriptions typically range from £129–£320 per month depending on your dose, with online prescription services often offering more competitive pricing than high street pharmacies. Understanding your options helps you find affordable access to this prescription-only weekly weight loss injection.
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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 Mounjaro Access in the UK
NHS access (free but may have waiting lists): Mounjaro is approved by NICE for use within specialist tier 3 weight management services. You'll need a GP referral and assessment by a specialist team. Availability varies by region — some areas have significant waiting lists. NHS access is completely free once prescribed, but demand currently exceeds supply in many ICBs.
Private prescription access: A UK-licensed prescriber can issue a prescription following an online clinical assessment. Private costs start around £129–£320 per month depending on your dose. This route typically has no waiting list and offers faster access. Use our GLP-1 weight loss calculator to see projected outcomes at different doses before committing financially.
- Starting dose (2.5 mg) is usually cheaper than higher maintenance doses
- Some private providers offer discounted rates for 3- or 6-month upfront payment
- Prescription costs are separate from dispensing pharmacy costs
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.
Mounjaro Dose Titration and Cost Impact
Mounjaro requires dose titration — you start at 2.5 mg weekly and increase gradually every 4 weeks (2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg). Starting doses are significantly cheaper than maximum doses. Your prescriber determines whether you need to escalate beyond 5 mg based on your response and tolerance. Many people achieve good results at lower doses (5–10 mg), which cost less than the maximum 15 mg dose. When comparing prices, check whether you're looking at starting dose or maintenance dose costs.
Finding the genuinely cheapest option requires comparing both prescription issuing fees and pharmacy dispensing costs. Some online prescription services charge £30–£50 for the clinical assessment and prescription, whilst others include this in the medication price. GPhC-registered pharmacies must meet UK standards, so price differences often reflect service level rather than quality. Always verify that any provider is UK-regulated before proceeding — this ensures your prescription is legitimate and your medication is authentic.
- 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 cheaper on the NHS than private?
Yes — NHS access is completely free once prescribed. However, NHS waiting lists in many regions are currently 6–18 months. Private prescriptions cost £129–£320/month depending on dose but have no waiting list. For some people, paying privately to start immediately is worth the cost versus waiting for free NHS access.
Which Mounjaro dose is cheapest?
The starting 2.5 mg dose is cheapest. However, most people escalate to 5 mg or higher for effective weight loss. Your prescriber determines the right dose for you — going with the cheapest dose may not be clinically appropriate. Use our BMI calculator to track progress at any dose level.
Can I get Mounjaro cheaper by switching doses?
No — dose changes should only be made under prescriber guidance, not for cost reasons. Staying on a dose longer than clinically recommended, or switching down prematurely, may reduce effectiveness and waste money overall.
Are all private Mounjaro providers the same price?
No — prices vary between online prescription services and pharmacies. Comparison shop, but always verify the provider is GPhC-registered and UK-licensed. Cheapest isn't always best if customer support or prescription quality is poor.
Do prescription costs include the actual medication?
No — prescription issuing fees are separate from pharmacy dispensing costs. A provider may charge £40 for the prescription, then you pay the pharmacy separately (typically £129–£280 depending on dose). Always ask for the total cost upfront before proceeding.
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.