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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Tirzepatide For Sale in the UK — What You Need to Know
Tirzepatide (marketed as Mounjaro) is a prescription-only weight management injection licensed in the UK. It's not sold "over the counter" — you need a clinical assessment and prescription from a licensed prescriber before you can access it. Tirzepatide is a dual GIP and GLP-1 receptor agonist, which means it works differently to other weight loss injections like semaglutide (Wegovy). This guide explains how to access tirzepatide in the UK, what it costs, and what to expect.
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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.
How to Access Tirzepatide in the UK
There are two main routes to access tirzepatide in the UK: through the NHS or privately.
NHS Route: You can ask your GP for a referral to a tier 3 specialist weight management service. However, NHS access is limited and varies significantly by region. Waiting lists can be several months or longer, and not all ICBs (Integrated Care Boards) currently fund tirzepatide. You typically need a BMI of 30 or above (or 27+ with weight-related health conditions) to qualify.
Private Route: You can access tirzepatide through a private online consultation with a UK-licensed prescriber. After a clinical assessment (usually online), a prescription is issued if appropriate and dispensed by a GPhC-registered pharmacy. This route is usually faster than NHS referral and doesn't require a GP involvement. Costs typically range from £150–£300 per month depending on the dose, as tirzepatide comes in five different strengths from 2.5 mg up to 15 mg weekly.
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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.
Important Facts About Tirzepatide Costs and Prescription Requirements
Tirzepatide is expensive and costs vary. On the NHS, it's free at point of use but access depends on your local ICB's commissioning decisions. Privately, you pay for both the clinical consultation and the medication. Costs are typically per injection or per month's supply (four weekly injections).
A clinical assessment is always required — you cannot buy tirzepatide without a prescription, regardless of route. A prescriber will check your eligibility based on BMI, weight-related health conditions, medical history, and current medications. Tirzepatide may not be suitable if you have certain medical conditions (such as a personal or family history of thyroid cancer, or gastroparesis). Use our free GLP-1 weight loss calculator to estimate potential outcomes, and our BMI calculator to check your starting point.
- 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 tirzepatide available over the counter in the UK?
No. Tirzepatide is prescription-only and requires a clinical assessment before it can be prescribed. You cannot buy it without a valid prescription from a licensed UK prescriber. Both NHS and private routes require a prescription.
How much does tirzepatide cost in the UK?
On the NHS, tirzepatide is free but access is limited and varies by region. Privately, costs typically range from £150–£300 per month depending on the dose (2.5 mg to 15 mg). Some providers charge per injection (weekly doses), others monthly. Prices vary between different private pharmacies.
What's the difference between tirzepatide and semaglutide (Wegovy)?
Tirzepatide (Mounjaro) is a dual GIP and GLP-1 receptor agonist, while semaglutide (Wegovy) activates only the GLP-1 pathway. Clinical trials suggest tirzepatide may produce slightly higher average weight loss (~20.9% body weight vs ~15%), but individual results vary significantly.
Can I get tirzepatide on the NHS quickly?
NHS availability is limited and varies by region. Waiting lists for tier 3 weight management services can be several months to over a year in many areas. Private routes are typically faster, often resulting in a prescription within days of online consultation.
Do I need a GP referral to get tirzepatide privately?
No. Private tirzepatide prescribing doesn't require a GP referral. You can arrange a private online consultation directly with a UK-licensed prescriber. However, it's advisable to inform your GP that you're considering or using tirzepatide so they're aware of your treatment.
Ready to take control of your weight loss journey?
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