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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Best Places To Get Mounjaro Online in the UK
If you're looking to access Mounjaro (tirzepatide) in the UK, you have two main routes: NHS specialist weight management services or private online prescribing through registered UK pharmacies. Both require a clinical assessment from a licensed prescriber to confirm eligibility. Understanding where to access Mounjaro safely, what to expect, and how it compares to Wegovy can help you make an informed decision about weight management treatment. This guide explains your options, eligibility criteria, and what the prescription process involves 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 vs Private Access to Mounjaro
NHS access: Mounjaro (tirzepatide) is approved by NICE for use within NHS specialist weight management services. However, access is limited to tier 3 and tier 4 weight management clinics, not standard GP prescription. You'll need a referral from your GP, and availability varies significantly by region. Waiting lists in many areas extend to several months or longer.
Private access: GPhC-registered online pharmacies can dispense Mounjaro following an online clinical assessment with a UK-licensed prescriber. This route doesn't require NHS referral, and you can typically access treatment much faster—often within days. Costs vary by dose, ranging from approximately £129–£320 per month depending on your dose level and the provider.
- NHS: Free but limited availability and longer wait times
- Private: Faster access but requires payment upfront
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.
How Mounjaro Compares to Wegovy Online
Both Mounjaro and Wegovy are GLP-1-based weight loss injections available online in the UK, but they work differently. Mounjaro is a dual GIP and GLP-1 receptor agonist—meaning it activates two hormone pathways—with clinical trials showing average weight loss of approximately 15–21% of body weight on the maximum 15mg dose. Wegovy is a GLP-1 agonist only, with average weight loss around 14.9% on the maximum 2.4mg dose. Individual results vary considerably. Use our GLP-1 weight loss calculator to estimate potential outcomes at different dose levels, and our BMI calculator to confirm your baseline eligibility.
- 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?
Yes, Mounjaro (tirzepatide) is approved by NICE for NHS use, but only through specialist tier 3 and tier 4 weight management services, not standard GP prescription. You need a referral from your GP, and waiting lists vary by region—many areas have significant delays.
How much does Mounjaro cost privately in the UK?
Private costs typically range from £129–£320 per month depending on your dose. Starting doses are lower (2.5mg) and cost less; maximum doses (15mg) cost more. Prices vary between registered pharmacies, so it's worth comparing providers.
Do I need a prescription to buy Mounjaro online?
Yes, Mounjaro is prescription-only in the UK. You cannot buy it without a valid prescription from a UK-licensed prescriber. Online pharmacies require a clinical assessment before issuing a prescription to confirm eligibility and safety.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist; Wegovy (semaglutide) is GLP-1 only. Clinical trials show Mounjaro may support slightly higher average weight loss (~20.9% vs ~14.9%), but individual results vary significantly. Your prescriber will advise which is more suitable.
How quickly can I access Mounjaro privately online?
Private access is typically faster than NHS—often within 1–5 days of completing an online clinical assessment. NHS access requires referral and may involve waiting months. Your Mounjaro KwikPen will be delivered by registered post once the prescription is issued.
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.