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
Can You Get Mounjaro Without Seeing Your GP?
Yes, you can access Mounjaro (tirzepatide) in the UK without going through your GP, though there are important distinctions between NHS and private routes. Mounjaro is a prescription-only weight management injection that may help support weight loss alongside diet and exercise. In the UK, you have two main pathways: NHS specialist services (which typically require GP referral) or private prescription through an online clinical assessment. Understanding your options helps you make an informed decision about which route suits your circumstances and 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 vs Private Routes for Mounjaro in the UK
NHS route: Mounjaro (tirzepatide) is NICE-approved for use within NHS weight management services, but access is through tier 3 specialist multidisciplinary services. This typically requires a referral from your GP, though the GP referral is not strictly a "consultation" — it's a referral into specialist care. NHS waiting lists vary significantly by region, sometimes stretching months to years. Once accepted into a tier 3 service, a specialist prescriber will conduct a full clinical assessment before prescribing.
Private route: You can obtain a Mounjaro prescription from a UK-licensed prescriber without GP involvement through a private online consultation. This follows a clinical assessment by the prescriber, who will review your medical history, current medications, BMI, and weight-related health conditions. If approved, the prescription is dispensed by a GPhC-registered pharmacy. No NHS referral is needed. Use our GLP-1 weight loss calculator to explore potential outcomes, and our BMI calculator to check your current status before assessment.
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 Mounjaro Access: What to Expect
Private Mounjaro prescriptions typically require an online health questionnaire and consultation with a UK-licensed prescriber (usually a doctor or nurse prescriber). The assessment focuses on your BMI, weight history, any weight-related conditions (type 2 diabetes, high blood pressure, sleep apnoea), current medications, and allergies. If approved, you'll receive a prescription valid at GPhC-registered pharmacies. Costs vary by dose and provider, generally ranging from £130–£320 per month. Unlike NHS access, private prescribing doesn't involve waiting lists and offers more immediate availability. However, ongoing support and monitoring may be more limited compared to specialist NHS services, so discuss follow-up arrangements with your chosen provider.
- 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.
Do I need to see my GP to get Mounjaro privately?
No. Private Mounjaro prescriptions are issued following an online clinical assessment with a UK-licensed prescriber, not your GP. You don't need a GP referral or involvement. However, you should inform your GP that you're taking Mounjaro, especially if you're on other medications, so they can monitor for interactions.
What's the difference between Mounjaro and Wegovy for private prescribing?
Both are GLP-1-based weight management injections available privately in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro dosing goes up to 15mg weekly; Wegovy up to 2.4mg weekly. Clinical trials showed different average weight loss results — Mounjaro approximately 15–21% body weight, Wegovy approximately 15%. Individual results vary significantly. Your prescriber will assess which is more appropriate for you.
Can I switch from NHS to private Mounjaro, or vice versa?
Theoretically yes, but it requires careful coordination with prescribers. If you're on NHS Mounjaro through a tier 3 service and wish to switch to private, inform your NHS team and the private prescriber about your current dose to avoid safety issues. Similarly, if you start privately and later access NHS services, bring detailed records of your dose history and response. Always ensure continuity of care between providers.
What happens if I don't meet private prescriber eligibility?
Private prescribers assess eligibility based on BMI (typically 30 or above, or 27+ with weight-related conditions), medical history, and medication interactions. If you don't meet criteria or there are safety concerns, the prescriber will decline. You can try another provider, but criteria are generally consistent. Alternatively, request a GP referral to NHS tier 3 services, which may have slightly different assessment protocols.
Is private Mounjaro more expensive than NHS access?
Private Mounjaro typically costs £130–£320 monthly depending on dose, whilst NHS prescriptions cost £9.90 per item (if eligible for NHS prescriptions). However, NHS access involves potential waiting lists and limited choice of prescriber. Private access is faster but at higher cost. Consider your budget, urgency, and preference for ongoing specialist support when deciding which route suits you.
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.