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 Buy Tirzepatide Online in the UK
Tirzepatide, the active ingredient in Mounjaro, is a prescription-only weight loss injection available in the UK through both NHS specialist services and private online prescribing. If you're searching for how to access tirzepatide in the UK, it's important to understand your options, costs, and the clinical assessment process required before you can obtain it. This guide explains the different routes to tirzepatide UK prescription, what you'll pay, and what happens next.
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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.
Private Tirzepatide Cost in the UK
Private prescriptions for tirzepatide typically cost between £129 and £320 per month, depending on the dose you're prescribed and the provider you choose. The starting dose (2.5 mg) is usually at the lower end of this range, whilst higher doses (15 mg) cost more.
Costs include the prescription consultation fee (usually £15–£40), the prescription itself, and the tirzepatide injection pen (a four-week supply). Some providers offer monthly payment plans or package discounts for longer commitments. You'll also need to factor in follow-up consultations, typically every 4–12 weeks, which may incur additional fees (usually £10–£25).
Private tirzepatide is dispensed by GPhC-registered pharmacies following a prescription from a UK-licensed prescriber. The prescriber will assess your eligibility based on BMI, medical history, and current medications before issuing a prescription. Individual results vary significantly — use our GLP-1 weight loss calculator to see projected weight loss at different doses based on clinical trial data.
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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.
NHS vs Private: Routes to Tirzepatide in the UK
NHS route: Tirzepatide is available through specialist weight management services (tier 3/4), but only via GP referral. NHS provision varies significantly by region, and waiting lists can be several months to over a year. Once approved, tirzepatide is free on the NHS.
Private route: Faster access — you can access an online consultation with a UK-licensed prescriber without NHS referral. The consultation typically takes 15–30 minutes via video or phone, and you'll answer health questions to determine eligibility. If approved, your prescription is sent to a GPhC-registered pharmacy for dispensing within 24–48 hours.
Eligibility for both routes: BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, or cardiovascular disease). South Asian, Chinese, Black African, or Black Caribbean adults may be eligible at lower BMI thresholds.
- 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 on the NHS in the UK?
Yes. Tirzepatide (Mounjaro) is approved for NHS use through specialist tier 3 and tier 4 weight management services. However, you must be referred by your GP, and regional availability and waiting times vary significantly. Some areas have waiting lists of 6–12 months or longer. NHS prescription is free once approved.
How much does tirzepatide cost privately in the UK?
Private tirzepatide typically costs £129–£320 per month depending on dose and provider. Starting dose (2.5 mg) is usually cheaper; maximum dose (15 mg) is more expensive. Add consultation fees (£15–£40 initially) and follow-up fees (£10–£25 per appointment) to your total cost.
What happens during an online tirzepatide consultation in the UK?
You'll complete a health questionnaire covering weight, medical history, current medications, and any weight-related conditions. A UK-licensed prescriber reviews this and may conduct a brief video or phone consultation (15–30 minutes). If eligible, they issue a prescription to a GPhC-registered pharmacy, which dispenses within 24–48 hours.
Can I use our GLP-1 calculator to estimate my tirzepatide costs?
Our weight loss calculator shows projected weight loss at different tirzepatide doses based on clinical trial data, but it doesn't calculate costs. Use it to understand potential outcomes; costs vary by private provider. Contact providers directly for pricing specific to your chosen dose.
What's the difference between NHS and private tirzepatide access?
NHS access is free but requires GP referral and specialist assessment, with long waiting lists. Private access is faster (days to weeks) but costs £129–£320 monthly. Both require clinical assessment; both confirm you're eligible based on BMI and health conditions.
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.