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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Mounjaro Headaches: UK Costs and How to Access
Headaches are a common side effect reported by people taking Mounjaro (tirzepatide) for weight management in the UK. If you're considering this prescription-only GLP-1 and GIP receptor agonist injection, understanding both the cost and how to access it — whether through NHS specialist services or private online prescribing — is essential. This guide covers UK pricing, eligibility, and the practical steps involved in getting Mounjaro, so you can make an informed decision about whether it's right for you.
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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.
Mounjaro Costs and Private Access in the UK
In the UK, Mounjaro is available through both NHS specialist weight management services and private prescribing routes. Private cost typically ranges from £130 to £320 per month, depending on the dose and provider. Costs vary because private prescribers set their own pricing, and you're paying for the full prescription without NHS subsidy.
Accessing Mounjaro privately involves an online consultation with a UK-licensed prescriber, who will assess your medical history, current medications, and weight management goals. If approved, your prescription is dispensed by a GPhC-registered pharmacy. The dose titration schedule — starting at 2.5mg and increasing gradually — means your first month's cost may differ from maintenance doses.
- Starting dose (2.5mg): Often lower cost as it's used for only 4 weeks
- Escalation doses (5mg, 7.5mg, 10mg, 12.5mg): Mid-range pricing
- Maintenance dose (15mg): Maximum dose, typically highest monthly cost
Each KwikPen contains 4 doses, lasting 4 weeks. When comparing costs across providers, check whether pricing is per pen or per month, and whether follow-up consultations are 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 Access vs. Private Route — Timeline and Eligibility
NHS route: Mounjaro is available through NICE-approved tier 3 specialist weight management services, but access varies significantly by region. Your GP must refer you to your local integrated care board's (ICB) specialist service. Waiting lists can extend from several months to over a year in many areas. Once approved, the NHS covers the full medication cost — but availability depends on local service capacity and commissioning decisions.
Private route: Much faster — typically 24–48 hours from consultation to prescription dispatch. No GP referral needed. Requires a clinical assessment via online questionnaire and video consultation with a UK-licensed prescriber. You pay privately but receive treatment immediately. Use our free GLP-1 weight loss calculator to help estimate potential outcomes, and our BMI calculator to confirm your eligibility before starting your journey.
NHS route: Mounjaro is available through NICE-approved tier 3 specialist weight management services, but access varies significantly by region. Your GP must refer you to your local integrated care board's (ICB) specialist service. Waiting lists can extend from several months to over a year in many areas. Once approved, the NHS covers the full medication cost — but availability depends on local service capacity and commissioning decisions.
Private route: Much faster — typically 24–48 hours from consultation to prescription dispatch. No GP referral needed. Requires a clinical assessment via online questionnaire and video consultation with a UK-licensed prescriber. You pay privately but receive treatment immediately. Use our free GLP-1 weight loss calculator to help estimate potential outcomes, and our BMI calculator to confirm your eligibility before starting your 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.
Can I get Mounjaro on the NHS in the UK?
Yes, Mounjaro (tirzepatide) is available through NHS specialist tier 3 weight management services via NICE approval. However, access varies by region and waiting lists are often lengthy. Your GP can refer you to your local service, but availability depends on your integrated care board's commissioning. Private access is faster and requires no NHS referral.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £130 to £320 per month depending on your dose and provider. Starting doses (2.5mg) may be cheaper as they're only used for 4 weeks; maintenance doses cost more. Check whether quoted prices are per pen or per month, and if follow-up consultations are included.
Is headache a common side effect of Mounjaro?
Headache is not listed as a very common or common side effect in Mounjaro's official guidance, though some people report it. More common side effects include nausea, diarrhoea, and vomiting, especially during dose escalation. If you experience persistent headaches while taking Mounjaro, discuss this with your prescriber — it may be related to dehydration, calorie restriction, or another factor.
What's the difference between Mounjaro and Wegovy for cost in the UK?
Mounjaro (tirzepatide) and Wegovy (semaglutide) are similar in private cost — typically £130–£320 monthly — though exact pricing varies by provider and dose. Mounjaro uses a dual GIP/GLP-1 mechanism with doses up to 15mg weekly, while Wegovy is a GLP-1-only injection with a maximum 2.4mg weekly dose. NHS access and waiting times vary by region and medication availability.
How quickly can I access Mounjaro privately?
Private access is typically very fast: most providers complete an online clinical assessment and issue a prescription within 24–48 hours. Your prescription is then dispensed by a GPhC-registered pharmacy and posted to you, often within 1–2 business days. This is significantly faster than NHS routes, which may involve referral processes and waiting lists lasting months.
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.