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
Free tracker included with every download this week
Mounjaro Shoulder Pain — Access and Cost in the UK
Shoulder pain is not a common side effect of Mounjaro (tirzepatide), though some patients report musculoskeletal discomfort during treatment. If you're experiencing shoulder pain while taking Mounjaro, it's important to discuss this with your prescriber. Whether you're accessing Mounjaro through the NHS or privately, understanding your options and costs can help you make informed decisions about this prescription weight loss injection and what to expect during treatment.
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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.
Mounjaro Costs and Private Access in the UK
Private Mounjaro costs in the UK vary depending on the dose and provider, but typically range from approximately £129 to £320 per month. A KwikPen (containing 4 weekly doses) usually costs between £130 and £280 depending on your starting or maintenance dose. Lower doses like 2.5 mg or 5 mg tend to be more affordable, while higher doses (10 mg, 15 mg) cost towards the upper end of this range.
Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. You do not need a GP referral to NHS specialist services — you can apply directly. The prescriber will evaluate your eligibility based on your BMI, health conditions, and medical history. If approved, your prescription is sent to a pharmacy, and Mounjaro is delivered to your home. This route typically takes 1–2 weeks from initial consultation to first injection.
- No waiting list — access within 1–2 weeks
- Prescription issued after online assessment
- Dispensed by a registered UK pharmacy
- Delivery to your home included
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 vs Private Routes — What's the Difference?
NHS access to Mounjaro is through tier 3 specialist weight management services, which requires a GP referral. Your GP assesses whether you meet NHS criteria (typically BMI ≥30, or BMI ≥27 with weight-related health conditions like type 2 diabetes or hypertension). If referred, you'll join a waiting list for your local Integrated Care Board — in many areas this can take several months to over a year. Once assessed by the specialist team, Mounjaro is prescribed and dispensed free on the NHS.
Private access bypasses NHS waiting lists entirely. You complete an online consultation, a licensed prescriber reviews your health information, and if suitable, issues a prescription within days. You then pay for each KwikPen at the pharmacy. Use our free GLP-1 weight loss calculator to estimate potential results at different doses, and our BMI calculator to check your starting point before consulting a prescriber.
- 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 shoulder pain a known side effect of Mounjaro?
Shoulder pain is not listed as a common side effect in clinical trials. However, some patients report musculoskeletal discomfort, which may be coincidental or related to gradual weight management affecting joint support. If you develop shoulder pain while taking Mounjaro, inform your prescriber — they can assess whether it's related to the medication or another cause.
How much does Mounjaro cost on the NHS?
Mounjaro is free on the NHS if prescribed through an NHS specialist weight management service. However, access requires a GP referral and assessment by a tier 3 service, and waiting times vary significantly by region — often several months. Private prescription costs are £129–£320 per month depending on dose.
Can I get Mounjaro prescribed privately without NHS referral?
Yes. Private online pharmacies offer Mounjaro following an online clinical assessment with a UK-licensed prescriber. You don't need NHS involvement. The prescriber reviews your eligibility (BMI, health conditions, medications) and issues a prescription if appropriate. Delivery typically takes 1–2 weeks from consultation.
What's included in the private Mounjaro cost?
Private costs usually cover the KwikPen (4 weekly doses), the clinical assessment, prescriber fees, and delivery to your home. Some providers may charge separately for consultations, so check the total cost before purchasing. You may need repeat consultations for dose increases.
How do I know if I'm eligible for Mounjaro?
You're typically eligible if you have a BMI of 30 or above, or BMI of 27–29 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, heart disease). Lower thresholds apply for South Asian, Chinese, Black African, or Black Caribbean adults. A prescriber will assess your individual eligibility during a consultation.
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.