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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Next Day Delivery Mounjaro in the UK — What You Need to Know
Next day delivery of Mounjaro (tirzepatide) in the UK depends on whether you access it through the NHS or privately. While NHS prescriptions typically involve longer waiting times through specialist tier 3 services, private prescriptions can be dispensed quickly by registered pharmacies following an online clinical assessment. This guide explains your options, NHS eligibility criteria, how the prescription process works, and what to expect with delivery timescales across both routes.
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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 Access to Mounjaro — Eligibility and Timeline
Access to Mounjaro through the NHS is provided via tier 3 specialist weight management services, not standard GP prescriptions. You'll need referral from your GP, but availability varies significantly by region and ICB (Integrated Care Board). NICE has approved tirzepatide for NHS use, but waiting lists for specialist services can be lengthy — often several months to over a year in many areas.
To be eligible, you typically need:
- BMI of 30 kg/m² or above, OR BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, cardiovascular disease)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds may apply from BMI 27.5
- Assessment by an NHS specialist team confirming suitability
If approved, your NHS prescription will be dispensed by an NHS pharmacy — but the entire process from referral to first dose can take considerable time due to service capacity constraints.
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 Access — Speed and Availability
Private prescriptions for Mounjaro can be dispensed much faster, sometimes within 24 hours or next day, following an online clinical assessment with a UK-licensed prescriber. You do not need NHS referral — private access is available directly to adults who meet eligibility criteria. A GPhC-registered online pharmacy will assess your suitability, issue a prescription if appropriate, and arrange delivery.
This route is faster because it bypasses NHS waiting lists, but involves direct costs (typically £120–£280 per KwikPen depending on dose). Private prescriptions still require genuine clinical assessment — you will not receive medication without a legitimate medical evaluation. Availability depends on the pharmacy's stock and your location within the UK.
- 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 next day delivery of Mounjaro on the NHS?
NHS Mounjaro is dispensed through tier 3 specialist services, which typically have longer timescales due to waiting lists and appointment availability. Next day delivery is not standard via NHS routes. Private prescriptions can often be dispensed faster, sometimes within 24 hours.
What are the NHS eligibility criteria for Mounjaro in the UK?
You need a BMI of 30 or above, or 27–29.9 with weight-related conditions (type 2 diabetes, high blood pressure, cardiovascular disease). South Asian and Black African/Caribbean adults may have lower BMI thresholds. Assessment by an NHS tier 3 specialist team is required.
How long does it take to get Mounjaro prescribed on the NHS?
The process typically involves GP referral, then assessment by a specialist team — overall timescale can range from several weeks to over a year depending on your region's waiting list capacity. Some areas have shorter waits than others; your GP can advise on local waiting times.
Is Mounjaro the same as tirzepatide, and does that matter for delivery?
Yes, Mounjaro is the brand name for tirzepatide. The branded KwikPen devices are standard — delivery speed depends on your access route (NHS vs private), not the medication name. Both routes deliver the same active ingredient.
What should I do if I want Mounjaro but NHS waiting times are very long?
You can explore private prescribing through a UK-licensed healthcare provider, which may offer faster access following a clinical assessment. Alternatively, discuss with your GP whether there are alternative NHS weight management options available locally while you wait.
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.