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 Second Dose: UK Cost & Access Guide
Your second Mounjaro dose (5 mg) marks the first maintenance phase of tirzepatide treatment in the UK. Understanding the cost, access routes, and what happens at this stage helps you plan your weight management journey. This guide covers private prescription costs, NHS availability, dose progression timings, and practical next steps for accessing your second injection in the UK.
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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.
Private Prescription Costs for Mounjaro in the UK
The second Mounjaro dose (5 mg) typically costs between £129 and £250 per month through private online prescribing in the UK, depending on your chosen provider. Each KwikPen contains four weeks of doses (one injection per week), so a single pen covers your second dose and three weeks of subsequent treatment.
- Private online consultation fee: typically £0–£49 (some providers include this in the medication cost)
- Prescription cost varies by provider — comparing options before starting is advisable
- Repeat prescriptions may cost slightly less once your initial assessment is complete
- You must stay on the 5 mg dose for a minimum of four weeks before escalating to 7.5 mg
Private access allows you to begin treatment without waiting for NHS tier 3 specialist services, which can have waiting lists of several months or longer in many UK regions.
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 Prescription Routes
NHS route: If approved through a specialist tier 3 weight management service, Mounjaro is provided free on prescription, including all subsequent doses and escalations. However, NHS access requires referral from your GP and assessment by a specialist team — availability and waiting times vary significantly by region (ICB).
Private route: Using a GPhC-registered online pharmacy, you can access Mounjaro without NHS referral. An online clinical assessment by a UK-licensed prescriber determines eligibility based on your health history, BMI, and medical conditions. If approved, your prescription is sent to the pharmacy for dispensing. This route is faster but requires private payment for each repeat prescription.
Try our free GLP-1 weight loss calculator to explore projected results and our BMI calculator to check your eligibility threshold.
- 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.
Will my GP prescribe Mounjaro for the second dose?
In most cases, no. Mounjaro is typically initiated and managed through NHS tier 3 specialist weight management services, not standard GP practice. Private online prescribers can prescribe your second dose if your initial prescription came through private access. If you started on the NHS, your specialist team will manage your second dose and escalations.
How long do I stay on the 5 mg second dose?
You must remain on 5 mg for a minimum of four weeks before your prescriber may increase to 7.5 mg. Some people benefit from staying longer at this dose. Your prescriber will assess your progress, tolerability, and side effects before deciding to escalate.
What if I can't afford the private cost of my second dose?
Contact your GP about NHS referral to a specialist weight management service — access is free if approved. Waiting times vary by region, but it's worth exploring. Some areas have shorter waits than others. Your GP can also check whether you meet NICE criteria for NHS-funded tirzepatide.
Can I switch from private to NHS Mounjaro after my second dose?
Yes, you can apply for NHS referral at any point. Your GP can refer you to a tier 3 specialist service. If approved, the NHS will continue your treatment from your current dose. Your private prescriber should be informed of this switch so your records are coordinated.
What should I expect at my second dose appointment?
For private prescriptions, a follow-up online consultation typically reviews your weight loss, side effects, tolerance, and whether you're ready to progress. For NHS patients, your specialist team will assess progress before confirming your second dose. Either way, prepare details of any nausea, digestive changes, or injection site reactions you've experienced.
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.