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 Dosage in the UK — Cost and Access
Tirzepatide, the active ingredient in Mounjaro, is available in the UK as a prescription-only weekly weight loss injection. Costs vary significantly depending on whether you access it through the NHS or private prescription route. Understanding dosage stages, pricing, and how to get tirzepatide in the UK helps you make informed decisions about weight management treatment alongside lifestyle changes.
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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.
Understanding Tirzepatide Dosage and Private Access Costs
Tirzepatide UK pricing depends on your access route. Privately, tirzepatide costs typically range from £129 to £320 per month, depending on the dose and provider. Treatment starts at a low dose (2.5 mg) and increases gradually over 16+ weeks, meaning early-stage costs are lower than maintenance doses.
Dosage progression follows this pattern: weeks 1–4 (2.5 mg), weeks 5–8 (5 mg), weeks 9–12 (7.5 mg), weeks 13–16 (10 mg), weeks 17–20 (12.5 mg), and week 21+ (15 mg maximum). Each dose requires a weekly KwikPen injection. Private providers typically charge per dose or per month. Our free GLP-1 weight loss calculator can help you understand potential progression and outcomes at different tirzepatide doses.
Private prescriptions require an online consultation with a UK-licensed prescriber who assesses your eligibility. If approved, your prescription is dispensed by a GPhC-registered pharmacy. This route bypasses NHS waiting lists, though costs are your responsibility.
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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 — Access and Costs Explained
NHS route: Tirzepatide is available through specialist tier 3 weight management services, but availability varies dramatically by region. NHS access typically involves a GP referral, specialist assessment, and potential waiting lists of many months. Once prescribed, tirzepatide is free on the NHS, but access is currently limited in many areas.
Private route: Faster access without waiting lists. You complete an online health questionnaire, have a consultation with a UK-licensed prescriber, and receive a prescription if clinically appropriate. This typically takes days rather than months. Private costs are your responsibility but offer certainty and speed. Both routes require genuine clinical assessment — tirzepatide is prescription-only and unsuitable for some individuals.
- 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 costs typically range from £129 to £320 per month depending on your dose and provider. Starting doses (2.5–5 mg) cost less than maintenance doses (10–15 mg). Prices vary between providers, so comparing options is worthwhile. Some providers offer discounts for upfront payment or dose commitments.
Is tirzepatide free on the NHS in the UK?
Yes, tirzepatide is free on the NHS if prescribed through specialist weight management services. However, NHS availability varies significantly by region. Many areas have limited access or long waiting lists. Your GP can refer you to tier 3 services, but you may wait several months. Private prescription is faster but costs you directly.
What's the difference between starting dose and maintenance dose costs?
Tirzepatide treatment starts at 2.5 mg and increases every 4 weeks. Starting doses cost less than maximum doses (15 mg). For example, 2.5–5 mg might cost £129–£160/month, while 10–15 mg costs £250–£320/month. Budget for approximately 16–20 weeks at escalating costs before reaching your maintenance dose.
How long does a tirzepatide KwikPen last?
Each KwikPen contains four weekly doses, so one pen lasts four weeks. At your maintenance dose, expect to use approximately one KwikPen per month. Starting doses use the same pens but inject lower volumes, so your actual pen usage depends on your current dose level.
What's the online consultation process for private tirzepatide UK?
You complete an online health questionnaire covering your medical history, current medications, and weight. A UK-licensed prescriber reviews your answers. If approved, you receive a prescription issued to a GPhC-registered pharmacy. The entire process typically takes 24–48 hours. You must be eligible (BMI 30+ or 27+ with comorbidities) and suitable for treatment.
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.