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
Is Wegovy Cheaper Than Mounjaro in the UK?
Both Wegovy and Mounjaro are prescription-only weight management injections available in the UK, but their costs differ significantly depending on whether you access them through the NHS or privately. On the NHS, both medications may be free if prescribed through specialist tier 3 services, though availability is extremely limited and varies by region. Privately, Wegovy and Mounjaro have different pricing structures due to their different dose ranges and manufacturers. Understanding the cost difference helps you weigh your options when considering GLP-1 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.
NHS Access and Private Pricing for Both Medications
NHS route: Both Wegovy and Mounjaro can theoretically be prescribed on the NHS through specialist weight management services following NICE guidance, meaning there would be no medication cost. However, NHS access is severely limited — only a small number of tier 3 services prescribe either medication, and waiting lists are extremely long in most regions (often 12–24+ months). Very few people currently access these medications through the NHS.
Private pricing: Wegovy typically costs between £145–£199 per month depending on dose and provider. Mounjaro KwikPen doses cost between £155–£249 per month depending on dose and provider. Wegovy's starting doses (0.25–0.5 mg) are cheaper than higher maintenance doses (1.7–2.4 mg). Mounjaro starts at 2.5 mg and escalates to 15 mg, so costs increase as you titrate. Private consultations are usually £20–£50, and costs vary between GPhC-registered pharmacies.
- Wegovy: most affordable at lower starting doses
- Mounjaro: costs vary more widely across the dose range
- Both require ongoing prescriptions (not one-off costs)
- NHS access available but extremely limited availability
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.
Which Medication Is More Cost-Effective for You?
Cost-effectiveness depends on your individual situation. Wegovy may appear cheaper initially at starting doses, but as you escalate to the full maintenance dose (2.4 mg), costs converge with Mounjaro. The real cost difference comes down to prescriber and pharmacy choice — prices vary significantly between private providers, sometimes by £50+ per month at the same dose. Rather than cost alone, your prescriber will assess which medication suits you based on clinical factors: Mounjaro uses a dual GIP/GLP-1 mechanism versus Wegovy's single GLP-1 pathway, and clinical trial data suggests slightly different average weight loss outcomes. Use our free GLP-1 weight loss calculator to project potential results with either medication, then discuss both options with your prescriber during a clinical assessment.
- 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.
Will Mounjaro vs Wegovy cost me anything on the NHS?
If prescribed through an NHS specialist tier 3 weight management service, both medications are free. However, NHS availability is extremely limited, and waiting lists are typically 12–24+ months in most regions. Very few people currently access either medication on the NHS. Most UK patients use private prescribing services instead.
Which medication is cheaper to buy privately in the UK?
Wegovy at lower starting doses (0.25–0.5 mg) may be slightly cheaper per month, typically £145–£160. Full-dose Wegovy (2.4 mg) costs £180–£199. Mounjaro costs £155–£249 depending on dose. Prices vary between GPhC-registered pharmacies, so shopping around can save £30–£60 per month.
Do I need to keep taking Mounjaro or Wegovy indefinitely?
Both medications are typically used as long-term treatments. Once you stop, weight regain is common within months. Your prescriber will discuss duration and ongoing cost with you during assessment. Some people use these medications for 6–12 months, others long-term — it depends on your health goals and clinical response.
Is Mounjaro KwikPen or Wegovy pen more expensive upfront?
Neither has a significant upfront device cost — the cost is for the medication itself. A Mounjaro KwikPen contains 4 weeks of injections; a Wegovy pen contains multiple doses. Monthly costs are comparable once you factor in dose equivalence. Actual savings depend on your dose and pharmacy choice.
How can I find the cheapest Wegovy or Mounjaro in the UK?
Prices vary between GPhC-registered online pharmacies by £30–£60 per month at the same dose. Get a prescription from a prescriber, then contact 2–3 different pharmacies for quotes. NHS eligibility (if available in your region) is free but requires GP referral and specialist assessment. Our free GLP-1 weight loss calculator can help you compare projected outcomes alongside cost considerations.
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.