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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Weight Loss & Healthy Salads: Medication Options in the UK
Eating healthy salads is a great foundation for weight loss, but if you're struggling to lose weight through diet alone, prescription medications are available in the UK for eligible adults. GLP-1 weight loss injections like Mounjaro and Wegovy are prescription-only medicines that work alongside healthy eating habits and increased physical activity. This guide explains your options and how to find out if you qualify for NHS or private access to weight management medication.
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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.
UK-Licensed Weight Loss Medications and Eligibility
Three GLP-1 medications are licensed in the UK for weight management:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist given as a once-weekly injection. In clinical trials, it helped participants lose an average of 15–21% of body weight over 72 weeks when combined with a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — A GLP-1 receptor agonist, also once-weekly, with average weight loss of approximately 15% in the STEP-1 trial.
- Saxenda (liraglutide) — A daily GLP-1 injection, typically used when weekly options are unsuitable.
You may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with a weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea). Lower thresholds apply for adults of South Asian, Chinese, Black African, or Black Caribbean heritage. Use our free BMI calculator above to check your BMI instantly, and our GLP-1 weight loss calculator to explore potential outcomes at different doses.
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.
NHS vs Private Access and Next Steps
In the NHS, weight loss medication is prescribed through specialist tier 3 weight management services — you'll need a referral from your GP, and availability varies significantly by region. Waiting lists can be long in many areas.
Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. This route does not require an NHS referral.
Either way, prescription weight loss medication works best alongside healthy eating (like salads), regular physical activity, and lifestyle changes — not instead of them. Start by discussing weight management options with your GP, who can assess your individual health and explain whether prescription treatment is appropriate for you. You can also track your progress using our free progress tracker once you've started any weight loss journey.
- 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 eating healthy salads alone help me lose weight?
Healthy salads are nutritious and support weight loss because they're low in calories and high in fibre, helping you feel full. However, weight loss requires a calorie deficit overall. If you're not losing weight with diet alone, your GP can discuss other options, including prescription weight management medication if you're eligible.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly GLP-1 injections licensed for weight management in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) activates only the GLP-1 pathway. Clinical trials showed slightly higher average weight loss with Mounjaro, but individual results vary significantly. Your prescriber will recommend the most suitable option for you.
How do I know if I'm eligible for NHS weight loss medication?
You may be eligible if your BMI is 30 or above, or 27–29.9 with a weight-related health condition like diabetes or high blood pressure. Speak to your GP about referral to a specialist weight management service. Lower BMI thresholds apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage. Use our free BMI calculator above to check your BMI.
Are weight loss injections available on the NHS?
Yes, but through specialist tier 3 weight management services rather than standard GP prescription. You'll need an NHS referral and may face waiting lists depending on your region. Private access is also available through online clinics following a clinical assessment. Availability and waiting times vary significantly across the UK.
Can I use weight loss injections if I'm just eating salads and not exercising?
Prescription weight loss medications like Mounjaro and Wegovy are most effective when used alongside a reduced-calorie diet and increased physical activity. Healthy salads are a great start, but your prescriber will expect you to make broader lifestyle changes. Weight loss medication supports your efforts — it doesn't replace the need for healthier habits overall.
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.