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 requires a clinical assessment from a licensed prescriber, whether through the NHS or privately. This guide explains your options, eligibility criteria, and how the prescription process works for this GLP-1 receptor agonist and GIP receptor medication. Mounjaro (tirzepatide) is a prescription-only weight loss injection that helps regulate appetite and blood sugar control. Understanding the difference between NHS and private routes can help you decide which path suits your situation best.
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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.
NHS Mounjaro Prescription — How It Works
NHS access to Mounjaro is through specialist tier 3 weight management services, not your GP's surgery. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS specialist weight management programmes for eligible adults.
- You must be referred by your GP to your local integrated care board's (ICB) specialist weight management service
- Eligibility typically requires a BMI of 30 kg/m² or above, or BMI of 27–29.9 kg/m² with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea)
- For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply due to higher cardiovascular risk at lower weights
- Once referred, you'll attend specialist appointments where a multidisciplinary team assesses your suitability — this includes medical history, current medications, and lifestyle factors
- If approved, prescriptions are issued by the specialist service, not dispensed privately
Waiting times for NHS specialist services vary significantly by region — some areas have waits of several months to over a year.
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 Mounjaro Prescriptions — Speed and Access
Private Mounjaro prescriptions are available through GPhC-registered online pharmacies without NHS referral. An online clinical assessment with a UK-licensed prescriber typically takes 24–48 hours, and prescriptions are issued if you meet eligibility criteria.
- Private prescriptions cost approximately £129–£320 per month depending on dose (starting at 2.5 mg, escalating to 15 mg maximum)
- Each KwikPen contains four weekly injections — one month's supply
- No NHS waiting list — treatment can begin within days of prescription
- You remain responsible for the full cost; private treatment is not subsidised
Both routes require a genuine clinical assessment. Never use Mounjaro without a prescription or medical supervision. Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses.
- 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 get Mounjaro on the NHS?
Yes, through specialist tier 3 weight management services if you meet eligibility criteria (BMI ≥30 or BMI 27–29.9 with health conditions). You need a GP referral. NICE has approved tirzepatide for NHS use, but availability and waiting times vary significantly by region. Contact your GP to ask about your local service.
How long does it take to get a private Mounjaro prescription online?
Private online assessments typically take 24–48 hours. Once approved, your prescription is sent to a GPhC-registered pharmacy for dispensing. You may receive your first KwikPen within 3–5 working days. The entire process from consultation to first injection usually takes under one week.
What's the cost of Mounjaro if I buy it privately in the UK?
Private Mounjaro costs approximately £129–£320 per month depending on your dose. Starting doses (2.5 mg) are cheaper; maximum dose (15 mg) costs more. Each KwikPen contains four weekly injections. Costs vary slightly between providers. Check with your prescriber or pharmacy for exact pricing at your dose level.
What happens during a Mounjaro clinical assessment?
A licensed prescriber will review your medical history, current medications, BMI, weight-related health conditions, and lifestyle. They'll check for contraindications (conditions that mean you cannot safely take Mounjaro) and assess whether tirzepatide is appropriate for you. The assessment is usually completed online via questionnaire and sometimes a brief consultation call.
Is private Mounjaro prescription the same as NHS Mounjaro?
The medication itself is identical — both are tirzepatide (Mounjaro). The difference is the route to prescription. NHS prescriptions come through specialist services; private prescriptions come from online prescribers and private pharmacies. Both require proper clinical assessment and are prescription-only medicines in the UK.
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.