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
What Does Mounjaro Do For Diabetics in the UK?
Mounjaro (tirzepatide) is a prescription-only injection that works differently for people with type 2 diabetes compared to those using it purely for weight management. Originally approved for diabetes, Mounjaro now also has UK licensing for weight management in adults with obesity or overweight with health conditions. The medication activates two natural hormone pathways—GIP and GLP-1—helping regulate blood sugar, reduce appetite, and support weight loss. If you have type 2 diabetes and are considering Mounjaro, understanding how to access it and what it costs in the UK is essential. Use our free GLP-1 weight loss calculator to explore potential outcomes, and check your BMI using our free calculator to understand your individual eligibility.
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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.
How Mounjaro Works for Type 2 Diabetes and Weight Management
For people with type 2 diabetes, Mounjaro addresses both blood sugar control and weight management simultaneously. The dual GIP and GLP-1 mechanism helps your pancreas release insulin when blood glucose rises, reducing hyperglycaemia (high blood sugar). This differs from some diabetes medications that work only on blood sugar without addressing weight. Clinical data shows that tirzepatide, the active ingredient in Mounjaro, can reduce HbA1c (average blood sugar over three months) by up to 2.5–3%, alongside weight loss of 15–21% of body weight on average.
- Improves insulin sensitivity and glucose control
- Reduces appetite and food cravings, supporting weight loss
- Slows gastric emptying, helping you feel fuller longer
- May reduce cardiovascular risk in people with diabetes
- Doses range from 2.5 mg to 15 mg once weekly, adjusted gradually over 20 weeks
Your GP or diabetes specialist will assess whether Mounjaro is suitable for your type 2 diabetes management based on your HbA1c level, current medications, and overall health. Many people continue using other diabetes medications alongside Mounjaro—your prescriber will advise on any adjustments needed.
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.
Mounjaro Cost and Access in the UK: NHS vs Private Routes
NHS access: Mounjaro for diabetes is available on the NHS through specialist services, though access varies significantly by region and ICB. Most patients access it via their GP referral to an endocrinology or diabetes specialist clinic. Waiting times can range from weeks to several months depending on your area. Your prescriber will check your medical history and blood sugar readings before prescribing, and the NHS KwikPen supply is provided free once approved.
Private prescription route: Mounjaro is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Private costs typically range from £150 to £350 per month depending on dose—2.5 mg to 5 mg injections cost less than the higher doses required for maximum effect. No NHS referral needed, and treatment can start within days. Always verify the pharmacy is GPhC-registered and the prescriber is UK-licensed before proceeding.
- 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.
Can I get Mounjaro on the NHS if I have type 2 diabetes?
Yes, Mounjaro is available on the NHS for type 2 diabetes management through specialist endocrinology or diabetes clinics. Your GP can refer you, but you'll need assessment by a diabetes specialist. Access and waiting times vary significantly by region. Private prescription is faster if you prefer not to wait for NHS referral.
What's the difference between using Mounjaro for diabetes versus weight loss?
Mounjaro addresses both conditions simultaneously. For diabetes, the focus is on HbA1c reduction and blood sugar control. For weight management alone, the focus is on appetite reduction and weight loss. The medication is identical—the difference is in monitoring and clinical goals. Your prescriber will define your treatment objectives.
How much does Mounjaro cost privately in the UK per month?
Private Mounjaro costs typically range from £150–£350 per month depending on your dose. Starting doses (2.5–5 mg) cost less; maximum doses (15 mg) cost more. Prices vary slightly between GPhC-registered pharmacies. Always confirm the total cost upfront, including any consultation fees.
Will my GP prescribe Mounjaro privately, or do I need an online consultation?
If you want Mounjaro privately, you'll need an online consultation with a UK-licensed prescriber (often through an online pharmacy service). Your own GP may not privately prescribe it unless you have an established relationship. NHS prescription requires GP referral to a diabetes specialist clinic.
What happens if I miss a dose of Mounjaro?
If you miss a dose within 4 days of your scheduled injection day, take it as soon as you remember and continue your normal weekly schedule. If more than 4 days have passed, skip that dose and take your next injection on the normal day. Never double-dose. Maintain at least 72 hours between injections.
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.