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
Weight Loss Injections On The NHS
Weight loss injections are available through the NHS, but access depends on your local area and eligibility criteria. The NHS offers GLP-1 receptor agonist medications like semaglutide (Wegovy) and tirzepatide (Mounjaro) through specialist weight management services for eligible adults. Understanding your NHS options, regional availability, and the referral pathway can help you explore whether prescription weight loss medication is right for you.
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.
How To Access Weight Loss Injections Through The NHS
Weight loss injections are prescribed through NHS specialist tier 3 and tier 4 weight management services, not standard GP prescriptions. Your GP can refer you to your local specialist service if you meet the eligibility criteria. Eligibility for NHS-funded weight loss medication typically includes:
- BMI of 30 kg/m² or above, or BMI of 27–29.9 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 may apply (from 27.5 kg/m²)
- Evidence of previous weight loss attempts through diet and lifestyle changes
NHS availability varies significantly by region and integrated care board (ICB). Some areas have long waiting lists — in many parts of the UK, waiting times can exceed 12–18 months. Your GP can advise you on availability and expected timescales in your area. Calculate your BMI using our free BMI calculator to check your starting point before speaking with your GP.
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.
Weight Loss Medications Available On The NHS
The NHS currently funds three GLP-1 medications for weight management: semaglutide (Wegovy), a once-weekly injection; tirzepatide (Mounjaro), also once-weekly; and liraglutide (Saxenda), a daily injection. Semaglutide works by activating the GLP-1 hormone pathway to reduce appetite and support weight management. Clinical trials showed semaglutide helped participants lose an average of approximately 15% of body weight — though individual results vary and outcomes depend on lifestyle changes, diet, and exercise. NHS weight management services provide these injections alongside dietary support, physical activity advice, and behaviour change coaching. Access our GLP-1 weight loss calculator to estimate potential outcomes at different doses and understand realistic expectations for your weight loss journey.
- 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 Wegovy and Ozempic?
Both contain semaglutide, but Wegovy is licensed for weight management while Ozempic is licensed for type 2 diabetes (at a lower dose). The NHS funds Wegovy for weight loss. Using Ozempic for weight loss is off-label use and not recommended without specialist medical supervision.
How long are NHS waiting lists for weight loss injections?
Waiting times vary dramatically by region. Some areas have waiting lists of 12–18 months or longer. Contact your local NHS weight management service or ask your GP about realistic timescales for your area. Private options are available without NHS waiting lists.
Can I get weight loss injections from my GP directly?
No. Weight loss injections are prescribed through specialist tier 3/4 NHS weight management services, not routine GP practice. Your GP can refer you, but the injection will be prescribed and managed by the specialist team, not your practice.
What happens if I don't meet NHS eligibility criteria?
If your BMI or health circumstances don't meet NHS thresholds, private prescribing is available through UK-licensed online prescribers. A clinical assessment will determine if the medication is suitable for you. Costs vary but typically range from £129–£320 monthly depending on dose.
Do I need to change my diet and exercise alongside NHS weight loss injections?
Yes. NHS weight management services prescribe injections alongside structured dietary support and physical activity advice. Weight loss medication works best combined with lifestyle changes. Your specialist team will provide a comprehensive programme, not just the injection.
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.