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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How to Get a Mounjaro Prescription Online in the UK
Getting a Mounjaro prescription online in the UK is possible through private prescribing services, though access differs from NHS routes. Mounjaro (tirzepatide) is a prescription-only, once-weekly injectable medicine licensed for weight management in UK adults. You'll need a clinical assessment from a UK-licensed prescriber to determine if it's suitable for you. This guide explains both private online access and NHS pathways, eligibility criteria, and what the assessment process involves.
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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 Online Mounjaro Prescriptions in the UK
Private online prescriptions for Mounjaro are available through GPhC-registered online pharmacies and telehealth services. These platforms connect you with UK-licensed prescribers who assess your eligibility via an online consultation. To access Mounjaro privately, you'll typically need to:
- Complete a detailed health questionnaire covering your weight, BMI, medical history, and current medications
- Have a video or telephone consultation with a UK-licensed prescriber
- Receive a prescription if the prescriber assesses you as clinically suitable
- Collect your Mounjaro from the GPhC-registered pharmacy
Private access is faster than NHS routes and doesn't require a GP referral. Costs range from approximately £129–£320 per month depending on your dose. You'll start on 2.5 mg and titrate up to your maintenance dose — typically 5–15 mg once weekly — over several weeks. Use our GLP-1 weight loss calculator to explore potential outcomes at different doses.
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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 Access and Eligibility Criteria
On the NHS, Mounjaro is available through tier 3 specialist weight management services, but access varies significantly by region. You'll need a GP referral, and waiting lists can be lengthy — sometimes months to years depending on your local Integrated Care Board (ICB). NHS eligibility requires a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds may apply. Check your local NHS weight management service website for specific criteria and referral processes in your area.
- 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.
What information do I need for an online Mounjaro assessment?
You'll need your current weight and height (use our free BMI calculator to have these ready), medical history, current medications, and any weight-related health conditions. Be honest about previous weight loss attempts and lifestyle. The prescriber will also ask about pregnancy plans, allergies, and whether you have any digestive problems or a history of pancreatitis.
Can I get Mounjaro on the NHS without waiting months?
NHS access is through specialist tier 3 weight management services via GP referral, but waiting lists vary by region. Some areas have shorter waits than others. Private online prescribing is faster if you're willing to pay. Contact your local NHS weight management service to understand current waiting times in your area.
How does the Mounjaro dose increase work?
Mounjaro uses a dose titration schedule, starting at 2.5 mg once weekly for 4 weeks, then increasing by 2.5 mg every 4 weeks up to 15 mg (your maximum dose). Your prescriber will guide you through this schedule. You don't increase the dose every week — it's every 4 weeks to allow your body to adjust.
Is Mounjaro the same as Wegovy?
No. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Both are prescription weight loss injections, but Mounjaro's dual mechanism may produce slightly different results. Clinical trials show both can support meaningful weight loss — individual responses vary.
What happens if the prescriber says I'm not eligible?
If you're not eligible for private prescription, ask your GP about NHS referral to tier 3 specialist services. If you don't meet their criteria, a prescriber may suggest alternative approaches such as behaviour change programmes, dietary support, or exploring other treatments. Your GP can discuss options with you.
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.