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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Weight Loss Groups in the UK: Medication and Support Options
Weight loss groups combine community support with structured programmes to help you manage your weight effectively. In the UK, you can access weight loss groups through the NHS, private services, and community organisations — many of which now integrate prescription weight management options like GLP-1 injections for eligible adults. This guide covers the different types of weight loss groups available, how prescription medication fits into weight management programmes, and how to find the right support for your needs.
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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 part of a weight loss group or considering joining one, prescription weight management may be available to you depending on your eligibility. The UK has three main licensed medications for weight loss:
- Mounjaro (tirzepatide) — a once-weekly dual GIP and GLP-1 injection that may help reduce appetite and support weight loss alongside lifestyle changes
- Wegovy (semaglutide) — a once-weekly GLP-1 injection licensed for weight management in UK adults
- Saxenda (liraglutide) — a daily GLP-1 injection option
You may be eligible for GLP-1 weight loss medication if you have a BMI of 30 kg/m² or above, or a BMI of 27–29.9 kg/m² with weight-related health conditions 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 apply. Clinical trials show that these medications, used alongside a reduced-calorie diet and increased physical activity, may help participants lose an average of 15–21% of their body weight — though individual results vary significantly.
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 Weight Loss Services vs Private Support
Weight loss groups operate across both NHS and private sectors in the UK. NHS-funded weight management programmes are delivered through tier 3 specialist services following GP referral, and typically include group support, behaviour change coaching, and sometimes prescription medication. However, waiting lists for NHS specialist services can be very long in many areas. Private weight loss groups range from online communities to in-person classes, and many now partner with online prescribing services to make GLP-1 medication accessible without NHS waiting times. Whether you choose NHS or private support, your prescriber will assess your individual eligibility for medication through a clinical consultation. Starting a conversation with your GP about weight management options is always a good first step — they can discuss what's available in your area and refer you to appropriate services.
- 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 difference between weight loss groups and weight loss medication?
Weight loss groups provide community support, shared learning, and accountability through group meetings or online communities. Prescription weight loss medication (like GLP-1 injections) is a medical treatment that requires a clinical assessment and prescription. Many modern weight loss programmes combine both — using group support alongside medication for better outcomes.
Do I need to be in a weight loss group to get prescription weight loss medication?
No. You can access prescription weight loss medication through NHS specialist services or private online prescribing without joining a formal group. However, many people find that combining medication with group support, dietary changes, and physical activity leads to better long-term results.
How do I know if I'm eligible for prescription weight loss medication in the UK?
Eligibility depends on your BMI and health conditions. You typically qualify if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like diabetes or high blood pressure. Lower thresholds apply for certain ethnic groups. Use our free BMI calculator above to check your BMI, then discuss eligibility with your GP.
Can I get GLP-1 weight loss injections through the NHS?
Yes, GLP-1 medications are available through NHS specialist tier 3 weight management services following GP referral. However, availability and waiting times vary significantly by region. Private online prescribing services also offer these medications without NHS referral, following a clinical assessment.
How much weight can I expect to lose with medication and a weight loss group?
Clinical trials show average weight loss of 15–21% of body weight with GLP-1 medication, alongside reduced-calorie diet and physical activity. However, individual results vary considerably based on your starting weight, adherence, and other factors. Try our GLP-1 weight loss calculator to estimate potential outcomes at different medication doses.
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.