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
NICE Tirzepatide Approval — What It Means for NHS Access
NICE (the National Institute for Health and Care Excellence) has approved tirzepatide, branded as Mounjaro, for use within NHS specialist weight management services in the UK. This approval means eligible adults can access this prescription weight loss injection through the NHS rather than only through private providers. Understanding NICE approval, eligibility criteria, and the NHS pathway can help you determine if tirzepatide 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 NICE Approval Works and What It Means
NICE guidance approves medications for NHS use based on clinical evidence, cost-effectiveness, and patient benefit. Tirzepatide received NICE approval because clinical trials demonstrated its effectiveness for weight management, and the health benefits justify its cost to the NHS.
This means tirzepatide (Mounjaro) is now an available treatment option within NHS specialist weight management services, though access varies significantly by region. Each Integrated Care Board (ICB) has its own commissioning decisions, so availability and waiting times depend on where you live.
- Clinical evidence: SURMOUNT trials showed tirzepatide helped participants lose an average of 15–21% of body weight
- NHS funding: NICE-approved medications are eligible for NHS funding through specialist services
- Regional variation: Availability depends on your local ICB's budget and commissioning decisions
- Prescription-only: Tirzepatide requires a prescription and clinical assessment before use
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 Eligibility and How to Access NICE-Approved Tirzepatide
To access tirzepatide through the NHS, you must meet clinical eligibility criteria and be referred to a tier 3 (specialist) weight management service. Your GP can refer you if you have a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease.
After referral, a specialist team will assess you further, including your overall health, any medical conditions, and whether tirzepatide is appropriate for you. Use our free BMI calculator to check your personal BMI and see if you may meet initial eligibility thresholds. Our GLP-1 weight loss calculator can also help you understand potential weight loss projections with tirzepatide treatment.
- 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 is the difference between NICE approval and NHS availability?
NICE approval means the medication has been assessed as clinically effective and cost-effective for NHS use. However, NHS availability still depends on whether your local ICB (Integrated Care Board) has commissioned the service and has funding available. NICE approval removes one barrier, but regional commissioning decisions mean access varies across the UK.
How long are NHS waiting lists for tirzepatide?
Waiting times vary significantly by region and current demand. Some areas have waiting lists of several months to over a year. You can ask your GP about typical waiting times in your area when you request a referral to a specialist weight management service.
Can I get tirzepatide privately if the NHS waiting list is too long?
Yes. If NHS waiting lists are not viable for you, tirzepatide is available through private prescription from UK-licensed prescribers following an online clinical assessment. Private access is typically faster but involves costs ranging from approximately £129–£320 per month depending on your dose.
Do I still need to follow a diet and exercise plan with tirzepatide?
Yes. NICE guidance and clinical trials show that tirzepatide works best alongside a reduced-calorie diet and increased physical activity. The medication supports your efforts but is not a replacement for lifestyle changes. Many people find it easier to make dietary changes because tirzepatide helps reduce appetite and food cravings.
What happens if I'm not eligible for NHS tirzepatide through NICE criteria?
If you don't meet the clinical criteria, you can discuss other options with your GP, such as NHS-funded weight loss programmes, lifestyle services, or private access to weight management medication. A GP assessment can clarify which pathways are appropriate for your individual circumstances.
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.