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 Meal Plan for Weight Loss in the UK
A free meal plan can be a helpful starting point for weight loss, but many people find that combining dietary changes with professional support gives better results. In the UK, you have several options available — from self-guided meal planning to prescription weight management medications. This guide covers both dietary approaches and NHS-approved medication options that may help if lifestyle changes alone haven't worked. Understanding what's available to you is the first step toward sustainable weight management.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Prescription Weight Loss Medications
If you're looking to lose weight and manage it long-term, several prescription-only weight loss medications are licensed in the UK. These are available alongside dietary and lifestyle support, not instead of them.
- Mounjaro (tirzepatide) — a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist. In clinical trials, people using Mounjaro lost an average of 15–21% of their body weight over 72 weeks, though individual results vary.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical evidence shows average weight loss of around 15% of body weight when combined with a reduced-calorie diet and increased physical activity.
- Saxenda (liraglutide) — a daily GLP-1 injection, another option available through the NHS and private prescription.
You may be eligible for these medications if you have a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our free GLP-1 weight loss calculator to explore potential weight loss projections 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 in the UK
NHS access: Prescription weight loss medications are available through NHS specialist tier 3 weight management services. You'll typically need a GP referral, and availability varies significantly by region and local commissioning decisions. Waiting lists can be lengthy in some areas.
Private access: You can access these medications through GPhC-registered online prescribers without an NHS referral. A licensed prescriber will assess your eligibility through an online consultation, and if appropriate, issue a prescription to a registered pharmacy. This route is faster but involves costs ranging from approximately £129–£320 per month depending on dose.
Talk to your GP about what's available in your area. They can discuss whether prescription weight loss medication is suitable for you and refer you to specialist services if appropriate. Check your BMI using our free BMI calculator above to understand where you stand on NHS weight management thresholds.
- 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.
Can I get a free meal plan for weight loss on the NHS?
The NHS offers free weight management support through tier 1 programmes, including digital tools and community-based weight loss plans. Your GP can refer you to local services. Tier 3 specialist services (where prescription medications are prescribed) are free on the NHS if you meet eligibility criteria and your local service has capacity.
Are prescription weight loss injections available on the NHS in the UK?
Yes, Mounjaro, Wegovy, and Saxenda are approved for NHS use in specialist weight management services. However, availability varies significantly by region, and waiting lists can be long. Private prescription is an alternative if NHS access is limited in your area.
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. Both are once-weekly injections. In trials, Mounjaro showed slightly higher average weight loss (15–21%) compared to Wegovy (around 15%), though individual results vary significantly.
How much weight can I expect to lose with prescription medication?
Results vary considerably between individuals. On average, clinical trials show 15–clinically studied weight loss with these medications when combined with a reduced-calorie diet and increased physical activity. Your GP or prescriber can discuss realistic expectations based on your personal circumstances.
Do I need to pay for weight loss medication privately?
On the NHS, specialist weight management services are free if you're eligible and referred through your GP. Private prescription medications cost between £129–£320 per month depending on the medication and dose. Some people use both — exploring NHS options first, then considering private prescription if waiting times are long.
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.