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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Zepbound Tirzepatide — NHS Access & UK Eligibility
Zepbound is the brand name for tirzepatide, a prescription-only weekly weight loss injection licensed in the UK. As a dual GIP receptor and GLP-1 receptor agonist, it works differently from single-mechanism weight loss medications. Understanding NHS eligibility, prescribing pathways, and how tirzepatide is accessed through UK health services can help you explore whether this medication might be suitable for your health goals. This guide covers everything you need to know about Zepbound tirzepatide in a UK context, including NICE guidance and NHS tier 3 services.
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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.
NHS Eligibility & UK Prescribing Pathways for Tirzepatide
NHS eligibility for tirzepatide (Zepbound): Adults in the UK may access tirzepatide through NHS specialist weight management services if they have a BMI of 30 kg/m² or above, or a BMI of 27–29.9 kg/m² with at least one weight-related health condition such as type 2 diabetes, hypertension, dyslipidaemia, or cardiovascular disease.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS applies lower BMI thresholds due to increased metabolic risk at lower weights — eligibility may begin at BMI 27.5 kg/m² or above.
Prescribing through NHS tier 3 services: Tirzepatide is prescribed through specialist tier 3 or tier 4 weight management services, not standard GP prescriptions. You will need a referral from your GP to access these services. NICE has approved tirzepatide for NHS use, but availability varies significantly across different integrated care boards (ICBs) and regions. Waiting lists in some areas can extend several months or longer.
Calculate your BMI instantly using our free BMI calculator above to check whether you may fall within NHS eligibility ranges.
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 Routes for Tirzepatide in the UK
NHS route: Free at point of use through tier 3 specialist services following GP referral and clinical assessment. However, availability is limited and varies by region — many areas have significant waiting lists. You cannot obtain tirzepatide from your GP directly; it must go through specialist services.
Private route: Available through GPhC-registered online pharmacies following a UK prescriber assessment. This route does not require NHS referral and typically offers faster access. Costs range from approximately £129–£320 monthly depending on dose and provider.
Both routes require a full clinical assessment confirming you meet eligibility criteria and have no contraindications. A weekly weight loss injection like tirzepatide works best alongside reduced-calorie diet and increased physical activity. Use our free GLP-1 weight loss calculator to explore projected outcomes at different doses.
- 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.
Is Zepbound available on the NHS in the UK?
Yes, NICE has approved tirzepatide (Zepbound) for NHS use in specialist tier 3 weight management services. However, availability varies by region and waiting lists can be lengthy. You must be referred by your GP to access NHS tirzepatide — it is not available through standard GP prescriptions. Check with your local integrated care board for availability in your area.
What does it mean that tirzepatide is a GIP receptor agonist?
Tirzepatide activates two hormone pathways: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). This dual mechanism is different from single GLP-1 medications. The combined effect may help regulate appetite, reduce cravings, and support feeling fuller after smaller meals. Clinical trials showed this dual action contributed to average weight loss of 15–21% of body weight.
What are the NHS eligibility criteria for tirzepatide?
NHS eligibility requires a BMI of 30 kg/m² or above, or BMI 27–29.9 kg/m² with weight-related health conditions (type 2 diabetes, high blood pressure, high cholesterol, cardiovascular disease, or sleep apnoea). For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds (27.5+) apply. Your GP assesses eligibility during referral.
How long are NHS waiting lists for tirzepatide prescription?
Waiting times vary significantly by region and local NHS capacity. Some areas offer relatively quick access within weeks, while others have waiting lists extending several months or longer. Contact your local integrated care board or specialist weight management service directly for current waiting times in your area.
Can I get tirzepatide privately without going through the NHS?
Yes. Tirzepatide is available through GPhC-registered online pharmacies following a clinical assessment by a UK-licensed prescriber. Private routes typically offer faster access than NHS services but involve monthly costs (usually £129–£320 depending on dose). Both routes require a prescription and clinical assessment confirming suitability.
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.