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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How to Get Tirzepatide in the UK — Cost & Access
Tirzepatide, branded as Mounjaro in the UK, is a prescription-only weekly weight management injection that works as a dual GIP receptor and GLP-1 receptor agonist. If you're interested in accessing tirzepatide for sale through UK prescriptions, you have two main routes: NHS specialist services or private online prescription. This guide explains the costs, eligibility, and how to access this medication in the UK.
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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.
Private Tirzepatide Cost in the UK
Private prescription tirzepatide (Mounjaro) in the UK typically costs between £129 and £320 per month, depending on your dose and the provider. Starting doses (2.5 mg and 5 mg) are generally at the lower end of this range, whilst higher maintenance doses (10 mg, 15 mg) cost more. The KwikPen device contains 4 weekly injections, so you'll need one pen per month on a consistent dose. Private access involves an online consultation with a UK-licensed prescriber, who will assess your eligibility based on BMI, health history, and weight-related conditions. If approved, your prescription is dispensed by a GPhC-registered pharmacy. Many providers offer subscription services, allowing you to set up regular monthly deliveries. Some also provide initial consultations at reduced rates or offer dose flexibility to manage costs. Always check what's included — some providers bundle consultations, whilst others charge separately for follow-up assessments.
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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 to Tirzepatide
The NHS route requires referral to a tier 3 or tier 4 specialist weight management service through your GP. This can take months or longer depending on your region, and availability varies significantly across England, Scotland, Wales, and Northern Ireland. Once prescribed through the NHS, the medication is free. The private route is faster — usually available within days to weeks — but you pay the full cost. Private access doesn't require NHS referral or GP involvement. Use our free GLP-1 weight loss calculator above to estimate potential results at different tirzepatide doses. Both routes require clinical assessment; you cannot buy tirzepatide without a valid prescription from a licensed prescriber in the UK.
- 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 buy tirzepatide without a prescription in the UK?
No. Tirzepatide (Mounjaro) is a prescription-only medication in the UK and requires an assessment by a licensed prescriber before dispensing. Purchasing without a valid prescription is illegal and potentially unsafe.
How much does tirzepatide cost on the NHS?
Tirzepatide is free on the NHS if prescribed through a specialist weight management service. However, NHS access typically requires referral from your GP and can involve waiting lists of several months. Availability depends on your local Integrated Care Board (ICB).
What's the cheapest way to get tirzepatide in the UK?
The cheapest option is NHS prescription (free), but access can be limited and slow. For faster private access, starting doses cost less (around £129–£180 per month) than higher maintenance doses. Some providers offer subscription discounts or flexible payment plans.
How do online tirzepatide prescriptions work in the UK?
You complete an online health questionnaire, have a video or phone consultation with a UK-licensed prescriber, and if approved, receive a prescription sent to a GPhC-registered pharmacy for dispensing. The process typically takes 24–48 hours from consultation to dispatch.
Is tirzepatide the same as semaglutide (Wegovy)?
No. Tirzepatide (Mounjaro) is a dual GIP and GLP-1 receptor agonist, whilst semaglutide (Wegovy) is a GLP-1 receptor agonist only. Clinical trials show tirzepatide may produce greater average weight loss, but results vary individually. Both are prescription-only in the UK.
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.