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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Online Mounjaro in the UK — NHS and Private Access
Online Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private prescribing routes. NICE has approved tirzepatide for weight management within the NHS, though access varies significantly by region. Private online prescribing offers faster access following a clinical assessment by a UK-licensed prescriber. This guide explains both routes, eligibility criteria, and what to expect when accessing Mounjaro online in the UK.
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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 and NICE Approval for Mounjaro
NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, NHS access is limited to tier 3 and tier 4 specialist services—not standard GP prescription. Most people must be referred to their local specialist weight management service, which can involve waiting lists of several months or longer depending on your region and NHS commissioning board (ICB) availability.
To access Mounjaro via the NHS, you typically need:
- A BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related comorbidities such as type 2 diabetes, hypertension, or cardiovascular disease
- Referral from your GP to the tier 3 specialist weight management service
- Assessment by the specialist team confirming suitability
- Lower thresholds may apply for South Asian, Chinese, Black African, or Black Caribbean adults due to higher health risks at lower BMI
Regional availability varies—some ICBs have more established tirzepatide programmes than others. Ask your GP whether Mounjaro is available in your area and what the current waiting time is.
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 Mounjaro Prescribing in the UK
Private online prescribing offers faster access to Mounjaro without NHS referral or waiting lists. UK-licensed prescribers can assess you via online consultation and issue a prescription if clinically appropriate, which is then dispensed by a GPhC-registered pharmacy. This route typically provides access within days to weeks rather than months.
Private Mounjaro costs vary by dose and provider, typically ranging from £129 to £320+ per month. Your prescriber will assess your medical history, current medications, and eligibility before prescribing. If prescribed, you'll receive detailed guidance on injection technique, storage (refrigerate unopened, room temperature after first use for up to 30 days), and side effect management. Use our free GLP-1 weight loss calculator to estimate potential weight loss at different Mounjaro doses, and the BMI calculator to understand your current health status in context.
- 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.
Can I buy Mounjaro online without a prescription in the UK?
No. Mounjaro (tirzepatide) is prescription-only in the UK. You must have a valid prescription from a UK-licensed prescriber before it can be dispensed by a pharmacy. Legitimate online routes involve a clinical assessment by a registered prescriber, not direct purchase without medical review.
How long does it take to get Mounjaro on the NHS?
NHS waiting times vary significantly by region. Referral to a tier 3 specialist weight management service can take weeks to months, and assessment and initiation may add further delays. Some regions have waiting lists of 6–12+ months. Private prescribing is typically much faster, offering access within 1–2 weeks in most cases.
What's the difference between NHS Mounjaro and private online Mounjaro?
The medication is identical. The difference is access speed, cost, and oversight. NHS Mounjaro is free at point of use but involves waiting lists and referral. Private Mounjaro costs £129–£320+ per month but is accessible without NHS referral and faster. Both routes require clinical assessment; private prescribers assess you online.
Am I eligible for Mounjaro through the NHS?
Generally, yes, if you have a BMI of 30+ or 27+ with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. However, regional availability varies—your GP can confirm whether Mounjaro is offered by your local NHS weight management service and what the current criteria are.
Do I need to take Mounjaro alongside diet and exercise?
Yes. Clinical trials showed Mounjaro works most effectively alongside a reduced-calorie diet and increased physical activity. It's a support tool, not a replacement for lifestyle change. Your prescriber will discuss realistic expectations—individual results vary, and weight loss is not assured.
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.