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
Scared to Take Mounjaro? Understanding UK Access & Cost
It's completely normal to feel anxious about starting Mounjaro—concerns about cost, side effects, and access are valid questions many people in the UK have. Understanding your options and what the process actually involves can help ease those worries. Whether you're considering NHS access through specialist services or exploring private prescription routes, knowing the real facts about tirzepatide availability and cost in the UK can help you make an informed decision with your GP or healthcare provider.
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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.
Mounjaro Cost in the UK—NHS vs Private Routes
Mounjaro is available in two ways across the UK: through the NHS or via private prescription. NHS access is free at the point of use but requires referral to a specialist tier 3 or tier 4 weight management service—availability and waiting times vary significantly by region and integrated care board (ICB). Many areas have substantial waiting lists.
Private prescription costs typically range from £120–£250 per month depending on your dose. Starting doses (2.5 mg) are generally less expensive than maintenance doses (15 mg). Each Mounjaro KwikPen contains 4 weekly injections. Private prescribing requires an online clinical assessment with a UK-licensed prescriber, usually costing £50–£100 for the consultation. No pharmacy name will pressure you into purchasing—legitimate GPhC-registered pharmacies require a valid prescription from a UK prescriber before dispensing.
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.
What to Expect: Getting a Mounjaro Prescription Safely
If you decide to pursue private prescription, the process is straightforward: complete an online health questionnaire, have a consultation with a licensed UK prescriber (often a pharmacist or doctor), and if approved, receive a prescription to be dispensed by a GPhC-registered pharmacy. You'll be asked about your weight, BMI, health conditions, current medications, and allergies. Use our free BMI calculator to have your exact BMI ready—prescribers will need it for assessment. The consultation typically takes 15–30 minutes. If you're not approved, the prescriber will explain why and may suggest NHS referral instead.
NHS route: ask your GP about referral to specialist weight management services in your area. This is free but may involve waiting months for an appointment.
[Section 3 content continued for practical next steps]- 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 Mounjaro available on the NHS in the UK?
Yes, NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, access is limited to tier 3 or tier 4 specialist services, requires GP referral, and waiting lists can be very long—sometimes 6–18 months depending on your region. Free treatment once approved, but availability varies by ICB.
How much does Mounjaro cost privately in the UK?
Private Mounjaro typically costs £120–£250 per month depending on your dose. Starting dose (2.5 mg) is usually cheaper; maintenance doses (10–15 mg) cost more. Each pen is a 4-week supply. Add £50–£100 for the initial online consultation with a prescriber. Total first month: approximately £170–£350.
What's the difference between Mounjaro and Wegovy for cost?
Both are prescription-only weight loss injections in the UK. Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist; Wegovy (semaglutide) is GLP-1-only. Private costs are similar (£120–£250/month). Both require clinical assessment. Mounjaro doses are measured in mg weekly; Wegovy reaches 2.4 mg weekly maximum. Ask your prescriber which suits you better.
Is the online consultation safe for getting Mounjaro prescribed?
Yes, if you use a GPhC-registered pharmacy with a UK-licensed prescriber. They'll assess your health history, BMI, and medications just as a GP would. Be honest about all health conditions and medications. The prescriber may decline if you're not suitable—this is a safety feature, not a rejection. You can appeal or ask for NHS referral.
What if I'm worried about Mounjaro side effects?
Common side effects include nausea, diarrhoea, and constipation, especially at the start—they typically reduce over time. Doses start at 2.5 mg (lowest), increasing gradually (dose titration) every 4 weeks. This slow escalation helps your body adjust. Serious side effects are rare. Speak to your prescriber before starting if you have concerns about specific conditions like pancreatitis risk or gallbladder issues.
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.