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 Mounjaro Online in the UK
Mounjaro (tirzepatide) is available online in the UK through licensed prescribers and GPhC-registered pharmacies, but it is always a prescription-only medicine requiring a clinical assessment. You cannot simply buy Mounjaro online without speaking to a healthcare professional first. Access is available through two main routes: NHS specialist weight management services (with longer waiting times) or private online prescribing (faster access). This guide explains how each route works, eligibility criteria, and what the online assessment involves.
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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.
Private Online Access to Mounjaro in the UK
Private online access to Mounjaro is the fastest route for most UK adults. You complete an online health questionnaire with a UK-licensed prescriber, who reviews your medical history, current medications, and weight-related health status. If assessed as clinically appropriate, the prescriber issues a prescription, which is then dispensed by a GPhC-registered pharmacy and delivered to your home.
- No NHS referral needed — direct access without waiting for specialist services
- Fast turnaround — typically prescription issued and delivered within 2–5 working days
- Flexible dosing — you and your prescriber can adjust doses based on your progress and side effects
- Cost — private prescriptions typically cost £129–£320 per month depending on dose (2.5 mg to 15 mg)
The online assessment is thorough — prescribers must confirm you meet eligibility criteria (BMI ≥30, or BMI ≥27 with weight-related health conditions), check for contraindications, and review your suitability for GIP/GLP-1 therapy. You will be asked about diabetes status, cardiovascular history, gallbladder or pancreatic problems, and current medications including oral contraceptives.
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.
NHS Access via Specialist Weight Management Services
NHS access to Mounjaro is available through tier 3 (specialist) and tier 4 (bariatric) weight management services, though NICE approval has been recent and availability varies significantly by region. You typically need a GP referral to access the NHS specialist pathway. Waiting times for NHS specialist services can range from several months to over a year in many areas, depending on your local Integrated Care Board (ICB) capacity.
Once assessed by the NHS specialist team, if Mounjaro is prescribed, it is dispensed free on the NHS. The specialist team provides ongoing monitoring and support. However, regional variation means some ICBs have already begun prescribing while others are still developing pathways. Your GP can advise whether Mounjaro is available through your local NHS services and how to access referral.
- 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 online without a prescription in the UK?
No. Mounjaro is prescription-only and always requires a clinical assessment by a licensed prescriber before you can access it, whether online or in person. Any service claiming to sell Mounjaro without a prescription is operating illegally. Legitimate online prescribers are registered with the General Medical Council (GMC) or Nursing and Midwifery Council (NMC), and pharmacies are registered with the GPhC.
How long does the online assessment for Mounjaro take?
The online health questionnaire typically takes 10–15 minutes to complete. The prescriber reviews it and makes a decision within 24–48 hours. If approved, the prescription is sent to the pharmacy, which usually dispatches within 1–2 working days. Total time from questionnaire to delivery is typically 2–5 working days.
What happens if I'm not eligible for Mounjaro online?
If the online assessment shows you do not meet eligibility criteria (e.g., BMI below 27, no weight-related health conditions, or medical contraindications), the prescriber will not issue a prescription. Some services offer alternative options or may suggest speaking to your GP about weight management support through NHS tier 1–2 services.
Can I switch between NHS and private Mounjaro prescriptions?
This depends on your circumstances and local NHS policy. If you start privately and later qualify for NHS prescribing, inform your GP so they can refer you to specialist services. Starting private does not prevent later NHS access, but there may be a gap between switching. Conversely, NHS prescriptions cannot be supplemented with private prescriptions for the same medication.
What if I'm taking oral contraceptives — can I use Mounjaro online?
Yes, but with important precautions. Mounjaro may reduce oral contraceptive absorption. Licensed prescribers will advise you to use additional contraception (e.g., condoms) or switch to a non-oral method for 4 weeks after starting Mounjaro and 4 weeks after each dose increase. Always declare all medications during your online assessment.
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.