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
How to Get Mounjaro Without a Subscription in the UK
Many people assume Mounjaro weight loss treatment requires a long-term subscription, but you have options in the UK. You can access tirzepatide (Mounjaro) through NHS specialist services or obtain a one-off prescription through private assessment without committing to ongoing monthly costs. Understanding your eligibility and access routes helps you find the most suitable pathway for your health needs.
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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 How It Works
In the UK, Mounjaro (tirzepatide) is available through NHS specialist tier 3 and tier 4 weight management services. You are not locked into a subscription — instead, you receive a prescription that you can manage through your NHS care pathway. NICE (the National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS weight management services, though availability varies significantly by region and ICB (Integrated Care Board).
- Eligibility: BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease)
- Access: Referral to NHS tier 3 services through your GP — no private subscription required
- Cost: Free on the NHS if approved and prescribed
- Availability: Waiting lists can be substantial in many areas; regional variation is significant
Once prescribed, you manage doses with your NHS prescriber — there is no compulsory subscription model. However, NHS availability is not assured in all regions, and waiting times can extend several months.
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 One-Off Prescriptions — Mounjaro Without Long-Term Commitment
If NHS access is not available or waiting lists are too long, you can obtain a one-off private prescription for Mounjaro from a UK-licensed prescriber following an online clinical assessment. This is not a subscription — you pay per dose and purchase what you need.
- You complete an online medical questionnaire
- A UK prescriber assesses your suitability for tirzepatide
- If approved, you receive a prescription valid for a set period
- You purchase doses from a GPhC-registered pharmacy at your own pace
- You can stop or pause treatment at any time without penalty
Private costs vary by dose (typically £129–£320 per month depending on strength), but there is no subscription lock-in. Our GLP-1 weight loss calculator can help you understand projected outcomes at different doses to inform your decision.
- 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 Mounjaro available on the NHS in the UK?
Yes, NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, availability depends on your region and ICB. You'll need referral to a tier 3 service from your GP. Many areas have significant waiting lists, and not all regions offer it immediately.
Do I have to pay a monthly subscription for private Mounjaro?
No. When accessing Mounjaro privately, you purchase doses individually following a clinical assessment. There is no subscription model — you can buy one dose, take a break, or stop at any time. Costs vary by dose strength (typically £129–£320 per month equivalent).
What's the difference between tirzepatide and Mounjaro?
Tirzepatide is the active ingredient; Mounjaro is the brand name. They are the same medication. You may also hear the term tirzepatide used generically, particularly in NHS contexts, but on prescription you'll receive Mounjaro in the KwikPen device.
Can I switch between NHS and private Mounjaro?
Potentially, yes — but this should be managed carefully with your prescriber. If you start privately and later gain NHS access, your prescriber can transition you. Conversely, if NHS access becomes available while you're on private treatment, discuss switching with your GP or NHS specialist.
What dose will I be prescribed for Mounjaro weight loss?
Mounjaro starts at 2.5 mg weekly, with increases every 4 weeks up to a maximum of 15 mg. Your prescriber (NHS or private) will titrate your dose based on your response and tolerance. Use our free BMI calculator and GLP-1 weight loss calculator to understand your starting point and projected outcomes.
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.