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
Tirzepatide Injection Price — What You'll Pay in the UK
Tirzepatide (Mounjaro) is a prescription-only weekly weight loss injection available in the UK through both NHS specialist services and private prescribing routes. The cost varies significantly depending on your access route: NHS provision is free at the point of care for eligible patients, whilst private tirzepatide prescriptions typically range from £129 to £320 per month depending on your dose. Understanding your options, eligibility criteria, and what to expect from each route will help you make an informed decision about accessing this GLP-1 receptor agonist medication.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Costs — What to Expect
Private tirzepatide costs in the UK typically range from £129 to £320 per month, depending on your dose and the private prescribing service you use. Each Mounjaro KwikPen device contains four weekly injections, so monthly supply costs reflect this four-week cycle.
- Starting doses (2.5–5 mg): approximately £129–£180 per month
- Mid-range doses (7.5–10 mg): approximately £180–£250 per month
- Higher doses (12.5–15 mg): approximately £250–£320 per month
Private prescribing typically involves an online consultation with a UK-licensed prescriber (usually £20–£50), followed by prescription dispensing through a GPhC-registered pharmacy. This route is faster than NHS access, with prescriptions often issued within 24–48 hours of assessment if clinically appropriate. You can try our GLP-1 weight loss calculator above to explore projected results at different doses, which may help inform your decision.
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.
NHS vs Private Access — How to Choose
NHS access is free but requires referral to a specialist tier 3 or tier 4 weight management service. Availability varies significantly by region (ICB), and waiting lists can be months to over a year in many areas. Your GP can refer you if you meet eligibility criteria (BMI ≥30, or BMI ≥27.5 with weight-related health conditions like type 2 diabetes or high blood pressure).
Private access is faster and doesn't require NHS referral, but you pay the full prescription cost. An online consultation with a prescriber takes 10–15 minutes, and your medical history is reviewed to assess suitability. Both routes are legitimate — choose based on urgency, budget, and whether you prefer a faster private route or free NHS provision if you can access it.
- 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.
How much does tirzepatide cost privately in the UK?
Private tirzepatide (Mounjaro) costs between £129 and £320 per month depending on your dose, with initial online consultations costing £20–£50. Each monthly supply is four KwikPen devices (one injection per week). Costs are higher for maximum doses (15 mg) than for starting doses (2.5 mg).
Can I get tirzepatide free on the NHS?
Yes, if you're eligible and referred to an NHS specialist weight management service by your GP. NHS provision is free at the point of care, but waiting times vary significantly by region and can be several months. Eligibility typically requires BMI ≥30 or ≥27.5 with weight-related health conditions.
What's the difference between Mounjaro and Wegovy pricing?
Both are typically priced similarly in the private market (£129–£320/month), though exact costs vary by provider and dose. Mounjaro is a dual GIP and GLP-1 receptor agonist, whilst Wegovy is GLP-1 only. Pricing is comparable, but your prescriber will assess which is most appropriate for you.
Do I need a consultation before getting a private tirzepatide prescription?
Yes, private tirzepatide prescriptions require an online consultation with a UK-licensed prescriber (usually 10–15 minutes). Your medical history and eligibility are assessed before a prescription is issued. This typically costs £20–£50 and is separate from the medication cost.
Is tirzepatide available on repeat prescription after the first month?
Yes, once your prescriber has assessed you and issued an initial prescription, you can often order repeat supplies without a new consultation. Some private services charge a small repeat prescription fee (£5–£15) or require a brief check-in every few months. Always confirm your provider's repeat prescription policy.
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.