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 Aches — Cost and Access in the UK
Muscle aches and injection site discomfort are common side effects when starting Mounjaro (tirzepatide), the once-weekly GLP-1 and GIP receptor agonist approved for weight management in the UK. Understanding the cost of accessing Mounjaro privately and through the NHS, plus knowing what to expect with injection site reactions, helps you make an informed decision about this prescription medication. This guide covers UK access routes, costs, and practical information about managing aches during treatment.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
UK Cost and Private Access for Mounjaro
Mounjaro is a prescription-only medicine available in the UK through NHS specialist weight management services or via private online prescribing. Private access typically costs between £129 and £300 per month depending on your dose and provider — as you titrate from the starting 2.5 mg dose up to the maximum 15 mg, costs may vary month to month.
When accessing Mounjaro privately, you'll need an online consultation with a UK-licensed prescriber who assesses your suitability based on your BMI, health conditions, and medication history. The KwikPen device (containing 4 weekly doses) is then dispensed by a GPhC-registered pharmacy. Delivery typically takes 2–5 working days. Private costs do not include consultation fees, which range from £30 to £100 depending on the provider. Unlike some other weight loss medications, there is no standard "Mounjaro price" across all providers — costs vary, so comparing options is worthwhile. Use our free BMI calculator to check your starting point before your consultation.
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 Access and What Aches Mean
NHS access to Mounjaro is through tier 3 specialist weight management services, typically accessed via GP referral. Availability varies significantly by region and ICB (Integrated Care Board), and waiting lists can be several months in many areas. If you receive Mounjaro on the NHS, there is no cost to you at point of use.
Muscle aches and injection site discomfort usually occur in the first few weeks as your body adjusts to the medication. These typically resolve within days to a week. However, if aches persist, worsen, or are accompanied by severe pain, swelling, or signs of infection at the injection site, contact your GP or prescriber. Rotating your injection site each week (stomach, thigh, upper arm) helps reduce localised aches. Our free GLP-1 weight loss calculator can help you project potential results and costs across different doses to help plan your treatment journey.
- 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.
How much does Mounjaro cost privately in the UK?
Private Mounjaro typically costs £129–£300 per month depending on your dose (2.5 mg to 15 mg) and provider. Consultation fees are separate, ranging from £30–£100. Costs are not subsidised and vary between providers, so it's worth comparing options before committing.
Can I get Mounjaro free on the NHS in the UK?
Yes. Mounjaro is available free on the NHS through specialist tier 3 weight management services. However, access requires a GP referral and assessment, and waiting lists are lengthy in many regions. Availability depends on your local ICB and commissioning decisions.
What injection site aches mean and when to worry?
Mild injection site aches, redness, or bruising are very common in the first few weeks. These usually resolve within days. Seek medical advice if pain is severe, lasts more than a week, or if you notice signs of infection like warmth, pus, or spreading redness.
How do I access Mounjaro privately online in the UK?
Book a consultation with a UK-licensed prescriber through a registered online service. You'll answer health questions, and the prescriber assesses your BMI, health conditions, and medication history. If approved, your prescription is sent to a GPhC-registered pharmacy for dispensing within 2–5 working days.
Is Mounjaro the same as Wegovy, and do they cost the same?
No. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Both are prescription-only and available privately and on NHS. Private costs are similar in range (£129–£300/month), but individual pricing varies by dose and provider, so compare before choosing.
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.