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
Lose Weight Injections and Other UK Options
If you're looking to lose weight in the UK, injections are just one option among many. This guide covers the full range of approaches available to you—from free NHS support and lifestyle changes through to prescription weight loss medication and specialist services. Whether you're exploring sustainable weight loss methods or considering prescription options, understanding what's available will help you make an informed decision 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.
Weight Loss Options Available in the UK
Weight management in the UK follows a tiered approach through the NHS, meaning you can access different levels of support depending on your needs and circumstances.
- Tier 1 (Self-help): Free NHS resources, digital tools like our BMI calculator and progress tracker, and community weight management programmes
- Tier 2 (Primary care): GP-led support, behaviour change programmes (such as the NHS Weight Loss Plan), and group weight management sessions
- Tier 3 (Specialist services): Multidisciplinary weight management teams where prescription weight loss medication (Mounjaro, Wegovy, or Saxenda) may be prescribed alongside lifestyle support
- Tier 4 (Bariatric surgery): Surgical options for severe obesity with significant health complications, available through specialist NHS centres
For nhs weight management, starting with your GP is always the right first step. They can assess your individual situation and guide you to the appropriate tier. If you're considering prescription weight loss injections, you'll typically need referral to a tier 3 specialist weight management service, though private prescribing is also available.
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.
How to Choose the Right Weight Loss Approach
The best weight loss approach depends on your BMI, health conditions, lifestyle, and personal preferences. Use our free BMI calculator above to establish your current position, then consider these factors:
- Your BMI: Lower BMIs may benefit from lifestyle changes alone; higher BMIs or those with weight-related conditions may benefit from medication support
- Your health conditions: Type 2 diabetes, high blood pressure, or sleep apnoea may make you eligible for prescription medication through the NHS
- Commitment to lifestyle change: Sustainable weight loss requires both dietary changes and increased physical activity—injections work best alongside these changes
- Your circumstances: NHS waiting lists vary by region; private options are available if you prefer faster access
Talk to your GP about what's right for you. They can discuss whether prescription weight loss injection options fit your situation and provide guidance on the most appropriate approach for sustainable weight loss.
- 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 weight loss injections are available on the NHS in the UK?
Tirzepatide (Mounjaro), semaglutide (Wegovy), and liraglutide (Saxenda) are the main prescription weight loss injections available on the NHS. These are prescribed through specialist tier 3 weight management services. Access depends on your BMI and health conditions, and varies by region. Your GP can refer you to your local service.
How quickly can I access weight loss injections in the UK?
NHS waiting times vary significantly by region—some areas have waits of several months to years. Private prescribing is typically faster, with assessment and prescription possible within days. However, all options require a clinical assessment from a UK-licensed prescriber before dispensing.
Are weight loss injections available privately in the UK?
Yes. Private weight loss injections are available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. This route doesn't require NHS referral and typically has shorter waiting times, though there is a cost involved.
Can I lose weight through lifestyle changes alone?
Yes. Many people achieve successful, sustainable weight loss through diet, physical activity, and behaviour change alone. Our free progress tracker can help you log your journey. For some people, this approach is sufficient; others benefit from additional support through prescription medication.
What does "sustainable weight loss" actually mean?
Sustainable weight loss means losing weight at a safe rate (typically 0.5–1 kg per week) and maintaining it long-term through permanent lifestyle changes. Crash diets and gradual weight management often lead to regain. The NHS recommends combining dietary changes, increased physical activity, and behaviour change for the best long-term results.
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.