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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Accessing Mounjaro Online in the UK
If you're searching for affordable Mounjaro online in the UK, it's important to understand the two routes available: NHS specialist services and private prescribing. Mounjaro (tirzepatide) is a prescription-only medication, so you'll need a clinical assessment before access, whether through your GP or a licensed online prescriber. This guide explains NHS eligibility criteria, how the private online route works, and what you can realistically expect in terms of cost and timeline.
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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.
NHS Access to Mounjaro — Eligibility and Waiting Times
Access to Mounjaro through the NHS is managed by specialist weight management services (tier 3 or 4), not your GP. You cannot obtain Mounjaro directly from your GP — you must be referred to a specialist service. NHS eligibility requires a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with a weight-related health condition such as type 2 diabetes, hypertension, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower thresholds may apply (BMI 27.5 or above).
Waiting lists for NHS specialist weight management services vary significantly by region. Many areas currently have waiting times of several months to over a year. Once assessed and approved, the NHS covers the full cost of Mounjaro, making it free at the point of prescribing. However, the extended wait means many people explore private options to start treatment sooner.
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.
Private Online Access — How It Works and Typical Costs
Private online prescribing offers faster access to Mounjaro without NHS referral. You complete an online consultation with a UK-licensed prescriber (doctor), who assesses your suitability based on your medical history and current health. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on your dose and the provider. Starting doses (2.5 mg KwikPen) are usually cheaper than maximum doses (15 mg). Many people find the private route viable for the first few months, then transfer to NHS care once their place on the specialist waiting list comes through.
- 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 Mounjaro available on the NHS in my area?
Mounjaro is approved for NHS prescribing through specialist tier 3 and tier 4 weight management services, but availability varies by region (ICB). Contact your GP to ask about referral to your local specialist weight management service. Waiting times are typically several months to over a year. Your GP can confirm whether services in your area currently prescribe Mounjaro.
What's the cheapest way to get Mounjaro in the UK?
The NHS route is completely free once prescribed through a specialist service, but waiting lists are long. Private online prescribing (£129–£320/month) is faster but costs money. Some people use private treatment initially, then switch to NHS once their appointment arrives, combining both routes.
How long does it take to get Mounjaro through a private online prescription?
Online consultations typically take 24–48 hours to complete and be assessed. If approved, your prescription is issued the same day and dispensed within 1–3 working days. You could have Mounjaro in hand within 4–5 days, compared to months on NHS waiting lists.
Do I need a clinical assessment before taking Mounjaro?
Yes. Whether you access Mounjaro through NHS or private routes, a qualified prescriber must assess your eligibility. This includes reviewing your BMI, weight-related health conditions, current medications, and medical history. This is a safety requirement and takes 15–30 minutes via online consultation.
Can I use the NHS later if I start Mounjaro privately?
Yes. Many people start treatment privately and then transition to NHS prescribing once their specialist referral is processed. Inform your GP that you've begun private treatment, and they can coordinate your transition to NHS care, potentially avoiding duplicate assessments.
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.