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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Getting Mounjaro Privately in the UK
Getting Mounjaro privately in the UK is an alternative to NHS waiting lists, allowing adults to access this prescription weight management injection through private online prescribing services. Unlike NHS specialist tier 3 services, private access does not require a GP referral. However, you will still need a clinical assessment from a UK-licensed prescriber before Mounjaro (tirzepatide) can be prescribed. This guide explains how the private route works, eligibility criteria, costs, and how it compares to NHS access.
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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.
How Private Mounjaro Access Works in the UK
Private Mounjaro access in the UK follows a straightforward process through registered online prescribing services. You complete an online health questionnaire, which is reviewed by a UK-licensed prescriber. If clinically appropriate, they will issue a prescription that is dispensed by a GPhC-registered pharmacy. The prescriber assesses your eligibility based on NHS criteria — a BMI of 30 kg/m² or above, or BMI of 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply.
Mounjaro comes as a KwikPen device containing four once-weekly doses. You inject yourself each week, rotating injection sites between your stomach, thigh, or upper arm. The prescriber will start you at 2.5 mg (weeks 1–4) and escalate gradually to your therapeutic dose, increasing every 4 weeks up to a maximum of 15 mg. Private prescribers typically offer doses ranging from 5 mg to 15 mg depending on availability and individual circumstances.
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 vs NHS Routes for Mounjaro
NHS access to Mounjaro requires referral to a specialist tier 3 weight management service through your GP. Availability is highly variable by region — some areas have long waiting lists of 12–24 months, whilst others have more limited access. The NHS covers the full cost of medication and specialist support. Private access skips NHS waiting lists entirely and does not require a GP referral. You can start treatment within days of a successful clinical assessment. However, you pay for the medication privately, typically ranging from £129–£320 per month depending on dose and provider. Both routes require a genuine clinical assessment and prescription — private access is not a shortcut that bypasses medical eligibility checks. Try our free GLP-1 weight loss calculator to estimate potential weight loss at different Mounjaro 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.
Do I need my GP's permission to get Mounjaro privately?
No. Private Mounjaro prescribing does not require GP involvement or referral. You apply directly to a private prescribing service. However, your GP may still be able to monitor your progress or manage any related health conditions if you inform them you are taking Mounjaro.
What are the typical costs of private Mounjaro in the UK?
Private Mounjaro typically costs £129–£320 per month depending on the dose and provider. Starting doses (2.5 mg and 5 mg) are usually at the lower end of this range, while higher therapeutic doses (10 mg to 15 mg) are at the higher end. Some services offer bulk-buy discounts.
How quickly can I start Mounjaro through a private service?
If your clinical assessment is approved, you can typically receive your first KwikPen within 2–7 days. This is significantly faster than NHS specialist services, which often have waiting lists of many months. The speed depends on the prescribing service and pharmacy processing times.
Are Mounjaro side effects different via private prescription compared to NHS?
No. The medication and side effects are identical regardless of whether it is prescribed privately or through the NHS. Common side effects include nausea, diarrhoea, constipation, and vomiting, particularly in the first few weeks. Serious side effects are rare but include severe stomach pain (possible pancreatitis) — seek urgent medical attention if this occurs.
Can I switch from private Mounjaro to NHS treatment?
Potentially, but it depends on your local NHS tier 3 service policies. If you are on private treatment and wish to transfer to NHS, discuss this with your GP. Your NHS team may accept continuity of treatment or may request restarting assessment. Each region handles this differently — contact your local integrated care board for guidance.
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.