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 Avocado Good For Weight Loss?
Avocados are nutrient-dense and support satiety, but they're high in calories — so portion control matters for weight loss. While dietary choices like including avocado can help, many people find that prescription weight management uk options provide additional support. If you're struggling with weight despite healthy eating habits, your GP can discuss whether prescription weight loss medication might be appropriate for you. This guide covers both nutrition and the medication options available to eligible UK adults.
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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.
Prescription Weight Loss Options Available in the UK
For adults who meet eligibility criteria, three prescription weight loss medications are licensed in the UK:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. In clinical trials, participants lost an average of 15–21% of their body weight alongside a reduced-calorie diet and increased physical activity. Doses range from 2.5 mg to 15 mg, injected once weekly.
- Wegovy (semaglutide) — a GLP-1 receptor agonist with an average weight loss of around 15% in clinical trials. Maximum dose is 2.4 mg, also injected once weekly.
- Saxenda (liraglutide) — a daily GLP-1 injection, though less commonly prescribed than Mounjaro or Wegovy.
All three are prescription-only medicines requiring clinical assessment. Individual results vary, and medication is used alongside dietary changes and physical activity, not instead of them. You can calculate your potential weight loss with our free GLP-1 weight loss calculator above.
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 Access and How to Find Out If You're Eligible
In the UK, prescription weight loss medication is available through two routes:
- NHS: Through specialist tier 3 weight management services. Your GP can refer you if you meet criteria (BMI ≥30, or ≥27 with weight-related health conditions like type 2 diabetes or high blood pressure). However, NHS access varies significantly by region and waiting lists can be long.
- Private: Through online clinics with UK-licensed prescribers, available without NHS referral. A clinical assessment determines suitability.
The best first step is to speak with your GP about your weight loss goals and whether prescription options might help you. They can assess your individual health and discuss what's available in your area.
- 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 avocado high in calories?
Yes. One medium avocado (around 150g) contains approximately 240 kcal. While avocados provide healthy fats, fibre, and nutrients that support satiety, portion control is important during weight loss. Small amounts (quarter to half an avocado) can be part of a balanced, calorie-controlled diet.
Can diet alone help me lose weight, or do I need medication?
Many people successfully lose weight through diet and exercise alone. However, if you've tried lifestyle changes without sustained results, prescription weight loss medication may help. Your GP can assess whether you're eligible and whether medication is appropriate for your situation. There's no shame in seeking additional support.
What does "BMI" have to do with weight loss medication eligibility?
BMI is used as a screening tool for weight loss medication eligibility in the UK. You may be eligible if your BMI is 30 or above, or 27 or above with weight-related health conditions. Use our free BMI calculator above to check your current BMI and understand where you stand.
How quickly do GLP-1 medications like Mounjaro and Wegovy work?
Weight loss typically becomes noticeable after 4–8 weeks, with more significant results over 12–20 weeks. However, individual results vary considerably. Clinical trials measured results over 68–72 weeks. Medication works best alongside sustained dietary changes and increased physical activity.
What if I'm not eligible for NHS weight loss medication?
If NHS access is limited in your area or you don't meet current criteria, private online clinics offer prescription weight loss medication following a clinical assessment. Costs vary but are typically £129–£320 per month depending on dose. Always ensure the clinic is registered with the GPhC (General Pharmaceutical Council).
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.