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
Free Weight Loss Eating Plans and UK Prescription Options
If you're looking for a free weight loss eating plan in the UK, you have several options: self-guided dietary approaches, NHS resources, and potentially prescription medication if you're eligible. The most effective weight loss combines sustainable eating habits with increased physical activity. For some adults, prescription weight management medication—available through NHS specialist services or private prescribing—may support your efforts alongside diet and lifestyle changes. This guide covers free eating plan strategies and how to explore prescription options with your GP.
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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 Prescription Weight Loss Options
If you're eligible, three prescription weight loss medications are available in the UK: Mounjaro (tirzepatide), a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide), a GLP-1 agonist; and Saxenda (liraglutide), also a GLP-1 agonist. Clinical trials show these medications may help you lose an average of 15–21% of body weight when combined with dietary changes and increased physical activity—though individual results vary significantly. Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply. All prescription weight loss medications are prescription-only and require a clinical assessment before being prescribed. You can access these through NHS specialist weight management services or via a private online consultation with a UK-licensed prescriber.
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 and Private Access Routes
NHS route: Speak to your GP about referral to a tier 3 specialist weight management service in your area. NHS availability varies by region, and waiting lists can be lengthy. Private route: GPhC-registered online pharmacies offer prescriptions following an online clinical assessment—no NHS referral required. Costs range from approximately £129–£320 per month depending on dose. Whether you pursue prescription medication or free dietary approaches, calculate your current BMI using our free BMI calculator to understand your starting point. Track your progress with our free progress tracker as you implement dietary changes and lifestyle modifications.
- 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 best free weight loss eating plan in the UK?
The NHS Weight Loss Plan is a free 12-week programme combining calorie-controlled eating with physical activity. The Mediterranean diet and intermittent fasting (16:8 or 5:2) also have strong evidence. A sustainable approach is a calorie deficit of 500 kcal daily, typically resulting in 0.5 kg loss per week. Consult your GP before starting any new diet, especially if you have existing health conditions.
Am I eligible for prescription weight loss medication on the NHS?
You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). South Asian, Chinese, Black African, and Black Caribbean adults have lower thresholds at BMI 27.5+. Your GP can assess your eligibility and refer you to specialist services if appropriate.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show Mounjaro may produce slightly higher average weight loss (15–21%) compared to Wegovy (around 15%), but individual results vary. Both are once-weekly injections. Your prescriber will recommend the most suitable option for you.
Can I get prescription weight loss medication privately without NHS referral?
Yes. GPhC-registered online pharmacies offer consultations with UK-licensed prescribers. If clinically appropriate, they issue a prescription that a registered pharmacy dispenses. This route doesn't require NHS referral but involves private cost (typically £129–£320/month). Always verify the provider is registered and use a legitimate, GPhC-registered pharmacy.
How much weight will I lose with prescription medication?
Clinical trials show Mounjaro users lost an average of 15–21% of body weight, and Wegovy users around 15%, over 68–72 weeks alongside diet and exercise. However, individual results vary significantly—some lose more, some less. These medications work best alongside a reduced-calorie diet and increased physical activity. Your GP or prescriber can discuss realistic expectations based on your circumstances.
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.