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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Quick Weight Loss Meal Plan: UK Prescription Medication Options
A quick weight loss meal plan works best when combined with the right support — and for many UK adults, that includes prescription weight management medication. If you're looking to lose weight, you may be eligible for NHS-approved treatments like Mounjaro or Wegovy, which can help alongside dietary changes and increased physical activity. This guide explains the prescription weight loss options available in the UK, who qualifies, and how to explore whether medication might support your weight management journey.
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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 Explained
Three prescription weight loss medications are currently licensed for weight management in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Each works as a GLP-1 receptor agonist — or in Mounjaro's case, a dual GIP and GLP-1 agonist — helping to regulate appetite and reduce food cravings.
Clinical trials show these medications can support meaningful weight loss when combined with a reduced-calorie diet and exercise. On average, patients taking Mounjaro at the maximum dose lost around 20.9% of their body weight over 72 weeks, whilst Wegovy users lost approximately 15% over 68 weeks. However, individual results vary significantly — weight loss depends on many factors including your starting weight, metabolism, and commitment to lifestyle changes.
All three are prescription-only medicines requiring a clinical assessment before being prescribed. They're not a replacement for healthy eating and physical activity — they're a tool to help support your weight management uk efforts alongside other changes.
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: How to Get Started
In the UK, you can access prescription weight loss medication through two routes: NHS specialist services or private online prescribing. NHS weight loss treatment is delivered through tier 3 specialist weight management services, typically after referral from your GP — though waiting lists vary significantly by region and availability can be limited.
Private access is available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. This route is often faster but involves a cost. Start by speaking with your GP about your weight loss goals — they can assess your eligibility, discuss whether prescription weight loss medication nhs support is appropriate for you, and explain local access options. Your GP can also calculate your BMI and check whether you meet the threshold for treatment (typically BMI 30 or above, or 27+ with weight-related health conditions).
Eligibility for weight loss medication nhs or private prescription depends on your BMI and health profile. You may qualify if you have a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related condition such as type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to higher health risks at lower weights.
Use our free BMI calculator above to check your current BMI instantly — this gives you a starting point for discussing eligibility with your GP. Your prescriber will also consider your medical history, current medications, and whether you're pregnant or planning pregnancy. Don't assume you're ineligible — have the conversation with your healthcare provider, as eligibility criteria are personalised.
- 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 lose weight quickly with prescription medication?
Prescription medications like Mounjaro and Wegovy can support weight loss, but results aren't instant. Clinical trials show average losses of 15–21% over several months, alongside a reduced-calorie diet and exercise. The NHS recommends losing 0.5–1 kg per week as a sustainable rate. Faster loss is possible but increases muscle loss risk and should only be pursued under medical supervision.
Will my GP prescribe me Mounjaro or Wegovy?
Your GP can assess your eligibility and may refer you to a specialist weight management service (NHS tier 3) if appropriate. However, not all GPs can prescribe these directly — access depends on your local area and NHS commissioning. Private online prescribing is an alternative route. Ask your GP about local options and waiting times.
What's the difference between a meal plan and medication?
A meal plan provides structure for calorie control and nutrition — essential for any weight loss. Prescription medications support appetite regulation and food cravings, making it easier to stick to that plan. They work together. Medication alone without dietary and lifestyle changes won't produce sustained results.
Am I eligible for weight loss medication on the NHS?
You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related health conditions like diabetes or high blood pressure. Lower thresholds apply for some ethnic groups. Use our BMI calculator to check your current BMI, then discuss eligibility with your GP — they'll assess your individual health profile.
How do I know if weight loss injections are right for me?
Only a prescriber can assess whether GLP-1 medication is suitable for your health situation. Discuss your weight loss goals, medical history, and any concerns with your GP. They'll consider your BMI, health conditions, current medications, and whether you're pregnant or planning pregnancy before recommending treatment.
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.