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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Cheaper Alternatives to Mounjaro in the UK
If you're looking for affordable weight management options in the UK, Mounjaro isn't your only choice. The NHS and private prescribers offer other GLP-1 receptor agonist alternatives that may be more cost-effective, including Wegovy (semaglutide) and Saxenda (liraglutide). This guide covers NHS eligibility, private pricing, and how these alternatives compare, so you can understand what's available and affordable for your situation.
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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 and Private Alternatives to Mounjaro
Wegovy (semaglutide) is often considered a primary alternative to tirzepatide. Clinically, Wegovy is a single GLP-1 agonist, while Mounjaro uses a dual GIP and GLP-1 mechanism. In clinical trials (STEP programme), Wegovy achieved average weight loss of approximately 14.9% body weight at the maximum 2.4 mg dose. NHS access is through tier 3 specialist weight management services, with eligibility the same as Mounjaro: BMI 30 or above, or BMI 27–29.9 with weight-related health conditions.
Saxenda (liraglutide) is a once-daily GLP-1 injection with lower maximum doses (3 mg) than Wegovy or Mounjaro. Average weight loss is typically 5–10% body weight. Saxenda has been available in the UK longer than Mounjaro, and private pricing can be competitive. NHS availability varies by region but is available through some specialist services.
Private costs range from approximately £129–£320 per month depending on the medication and dose, making private access potentially cheaper than some NHS waiting lists in regions with limited availability.
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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 Versus Private Costs and Access Routes
On the NHS, Mounjaro, Wegovy, and Saxenda are all prescription-only and accessed through tier 3 specialist weight management services. NHS access is free at point of use but waiting times vary significantly by region—some areas have waiting lists of months to years. Private prescribing offers faster access without NHS referral, requiring only an online clinical assessment with a UK-licensed prescriber. Private costs depend on the medication and dose; Saxenda daily injections can sometimes cost less per month than weekly Mounjaro or Wegovy, though this varies by provider. Calculate your potential weight loss and compare options using our free GLP-1 weight loss calculator to estimate outcomes at different doses.
To find the right option, check your eligibility using our free BMI calculator, which aligns with NHS criteria. Eligibility is the same for all GLP-1 medications: BMI 30 or above, or BMI 27–29.9 with conditions like type 2 diabetes, high blood pressure, or sleep apnoea. If you're in a region with long NHS waiting times, private prescribing may be more practical. Any prescriber will assess you individually to ensure the medication is clinically appropriate. Individual results vary significantly—some people lose more weight than others—but evidence suggests all three medications support meaningful weight loss alongside diet and activity changes.
- 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 Wegovy cheaper than Mounjaro in the UK?
Wegovy and Mounjaro private pricing is comparable, typically £129–£320 per month depending on dose and provider. Mounjaro's dual mechanism (GIP+GLP-1) may offer slightly more weight loss on average, but Wegovy is often considered a good-value alternative. On the NHS, both are free but access depends on your region's tier 3 services and current waiting lists.
Can I get Mounjaro alternatives on the NHS?
Yes. Wegovy and Saxenda are both NHS-approved for weight management through specialist tier 3 services. Eligibility is identical: BMI 30 or above, or BMI 27–29.9 with weight-related health conditions. NHS availability varies by region, and waiting times can be significant. Your GP can refer you to your local specialist weight management service.
How do Wegovy and Mounjaro compare in weight loss?
In clinical trials, Mounjaro achieved average weight loss of approximately 15–21% body weight, while Wegovy achieved approximately 14.9%. Both are taken once weekly. Mounjaro uses a dual GIP+GLP-1 mechanism, while Wegovy is a GLP-1 agonist only. Individual results vary—some people respond better to one than the other. Your prescriber can help decide which is most suitable for you.
What about Saxenda as a cheaper alternative?
Saxenda (liraglutide) is a once-daily GLP-1 injection with average weight loss of 5–10% body weight—typically lower than Mounjaro or Wegovy. Private pricing can be competitive, especially if daily injections suit your routine. NHS access is available through some specialist services. It's a valid alternative if once-daily injection administration suits you better.
How do I access private weight loss injections quickly?
Private prescribing requires an online clinical assessment with a UK-licensed prescriber. You'll answer health questions, and if approved, a prescription is issued to a GPhC-registered pharmacy. This typically takes 24–48 hours. No NHS referral is needed. Private access is faster than NHS specialist services in most regions but involves a cost.
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.