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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Free Weight Loss Training Plan — UK Medication Options
A weight loss training plan works best alongside the right support — and in the UK, that support includes access to prescription weight management options for eligible adults. Whether you're looking for lifestyle guidance, NHS resources, or information about prescription weight loss medication available in the UK, this guide explains your options. We'll cover how to build an effective weight management strategy, explore medications like Mounjaro and Wegovy that may help, and show you how to find out if you're eligible. Start by understanding your current weight and health status using our free BMI calculator above, then read on to discover what's available to you.
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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
For UK adults with a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions, prescription weight loss medications are available. Three main options are currently licensed in the UK:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, once-weekly injection, average weight loss 15–21% in clinical trials
- Wegovy (semaglutide) — a GLP-1 receptor agonist, once-weekly injection, average weight loss around 15% in clinical trials
- Saxenda (liraglutide) — a GLP-1 receptor agonist, daily injection, lower dose than Mounjaro/Wegovy
All three are prescription-only medicines requiring a clinical assessment before prescribing. Individual results with weight loss injections UK vary significantly — these medications work best alongside a reduced-calorie diet and increased physical activity. Our GLP-1 weight loss calculator can help you estimate 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 — How to Get Started
In the NHS, prescription weight loss medication is typically accessed through specialist tier 3 weight management services. Your GP can refer you, but access varies significantly by region and waiting times can be lengthy. Private access is available through GPhC-registered online prescribers following an online clinical assessment — this is often faster but involves a cost.
To find out if you're eligible, start a conversation with your GP about your weight management goals. They can assess your BMI, discuss any weight-related health conditions, and advise whether prescription medication is appropriate for you. Use our free weight converter to establish your current weight in metric if you normally think in stone and pounds, and track any progress using our progress tracker.
- 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.
Do I need a training plan to lose weight with Mounjaro or Wegovy?
Prescription weight loss medications are most effective when combined with a reduced-calorie diet and increased physical activity. While medication supports appetite control, a structured approach to nutrition and exercise maximises results. Many NHS weight management services provide dietary advice and behaviour change support alongside medication.
What's the difference between a free weight loss plan and prescription medication?
A free weight loss training plan typically focuses on diet, exercise, and behaviour change strategies. Prescription medications like Mounjaro and Wegovy work by reducing appetite and supporting feelings of fullness — they complement but don't replace lifestyle changes. The combination of both is usually most effective.
How quickly will I lose weight with GLP-1 medication?
The NHS recommends losing 0.5–1 kg per week for sustainable results. Weight loss with GLP-1 medications typically becomes noticeable within the first 4–8 weeks, though individual results vary. Patience and consistency with diet and exercise are important — gradual weight management can increase muscle loss risk.
Can I get prescription weight loss medication on the NHS?
Yes, if eligible. NHS access is through specialist weight management services (usually tier 3). Your GP can assess eligibility and refer you. Criteria typically include a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. Availability and waiting times vary by region.
What's the best first step if I want to lose weight in the UK?
Start by calculating your current BMI using our free BMI calculator to understand your health baseline. Then book a GP appointment to discuss your weight management goals. Your GP can advise whether prescription medication is suitable for you, refer you to specialist services if needed, or recommend lifestyle changes. They may also check for weight-related health conditions.
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.