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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Mounjaro Alternatives in the UK: Your Options
If you're exploring prescription weight loss options in the UK, Mounjaro isn't your only choice. Several other GLP-1 and dual-action receptor agonist medications are available, each with different costs, doses, and access routes. Whether you're considering NHS access through specialist weight management services or private prescriptions following an online consultation, understanding your alternatives helps you make an informed decision with your GP or healthcare provider.
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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.
What Are the Main Mounjaro Alternatives Available in the UK?
The primary UK-licensed alternatives to Mounjaro (tirzepatide) are Wegovy (semaglutide) and Saxenda (liraglutide). Wegovy is a once-weekly GLP-1 injection with a maximum dose of 2.4 mg, offering similar weekly convenience to Mounjaro but using a single hormone mechanism rather than Mounjaro's dual GIP and GLP-1 action. Saxenda is a daily injectable GLP-1 medication, requiring once-daily injections at home. In clinical trials, Wegovy helped participants lose an average of approximately 15% body weight, whilst Saxenda typically supports around 5–clinically studied weight loss on average. Individual results vary significantly. Both are prescription-only medicines requiring a clinical assessment before prescription. A key difference is that Mounjaro's dual mechanism may provide stronger appetite suppression for some patients, whilst Wegovy and Saxenda work through GLP-1 activation alone. Your prescriber can discuss which mechanism may suit your circumstances better.
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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
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NHS vs Private Access: Cost and Routes in the UK
Accessing weight loss injections through the NHS involves referral to a tier 3 specialist weight management service, usually from your GP. Availability varies significantly by region and waiting lists can be lengthy—sometimes several months to over a year. There is no direct cost to you on the NHS, but access depends on your BMI and local ICB (Integrated Care Board) commissioning. Private prescriptions are available through UK-licensed prescribers via online consultations, typically costing £129–£320 per month depending on the medication and dose. Private access is faster—often within days—and doesn't require NHS referral. Both routes require a clinical assessment to confirm eligibility. Use our free BMI calculator above to check whether you might meet eligibility criteria, and discuss either route with your GP.
- 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.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist with doses up to 15 mg weekly, whilst Wegovy (semaglutide) is a GLP-1-only injection with maximum dose 2.4 mg weekly. Clinical trials showed Mounjaro achieved average weight loss of approximately 15–21% body weight, and Wegovy approximately 15%. Both are once-weekly injections. Individual results vary, and your prescriber can advise which suits your health profile.
Can I get weight loss injections on the NHS?
Yes, through specialist tier 3 weight management services. Your GP can refer you if your BMI is 30 or above, or 27+ with weight-related health conditions. NHS access is free but waiting lists vary by region—sometimes several months. Private online prescriptions are faster (days) but cost £129–£320 monthly depending on dose.
How much do Mounjaro alternatives cost privately in the UK?
Private costs range from approximately £129–£320 per month, depending on the specific medication and dose. Higher doses cost more. This is for the medicine only; some providers may include consultation fees. Always check pricing with your prescriber before starting treatment.
Is Saxenda still available in the UK?
Yes, Saxenda (liraglutide) is still licensed for weight management in the UK and available through NHS and private routes. It's a daily injection rather than weekly. Average weight loss is typically lower than Mounjaro or Wegovy—approximately 5–10% of body weight in trials. Your prescriber can advise if it's appropriate for you.
How do I get a private prescription for weight loss injections?
You book an online consultation with a UK-licensed prescriber, usually through a private prescribing service. You'll discuss your medical history, current medications, and weight loss goals. If the prescriber assesses you as suitable, they'll issue a prescription to be dispensed by a GPhC-registered pharmacy. The process typically takes 24–48 hours from consultation to prescription. ```
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