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
What Is Jarro and How Does It Relate to UK Weight Management?
Jarro is not a recognised weight management medication in the UK health system. If you're searching for information about weight loss options available in the UK, you may be thinking of Wegovy (semaglutide) or Mounjaro (tirzepatide), which are prescription-only GLP-1 and dual GLP-1/GIP medications licensed for weight management. This UK health guide explains what weight management medications are actually available, how they work, and how to access NHS guidance for your personal health situation.
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-Licensed Weight Management Medications
If you're looking for prescription weight loss support in the UK, there are several evidence-based options available:
- Wegovy (semaglutide) — a once-weekly GLP-1 injection licensed for weight management. Clinical trials showed an average weight loss of approximately 15% body weight, though individual results vary.
- Mounjaro (tirzepatide) — a once-weekly dual GIP/GLP-1 injection. SURMOUNT trial data showed average weight loss between 15–21% depending on dose.
- Saxenda (liraglutide) — a once-daily GLP-1 injection, available through NHS specialist services in some areas.
All prescription weight loss medications require a clinical assessment before being prescribed. Your GP can refer you to your local NHS tier 3 weight management service, or you can access private prescribing through a UK-licensed online prescriber.
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.
How to Access Weight Management Support in the UK
The NHS offers a structured weight management pathway starting with self-help resources and digital tools through tier 1 services, progressing to GP-led support at tier 2, and specialist prescription medication through tier 3 specialist services. Many areas have significant waiting lists. Private online prescribing offers faster access without NHS referral — a prescriber will assess your eligibility based on your BMI and health conditions. Use our free BMI calculator above to check your current BMI and understand whether you may be eligible for weight management support. Alongside any medication, healthy weight management requires reduced-calorie diet and increased physical activity.
- 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 Jarro a weight loss medication available in the UK?
Jarro is not a recognised weight management medication licensed in the UK. If you're researching weight loss options, you may be interested in Wegovy or Mounjaro, which are prescription-only GLP-1 and GIP/GLP-1 medications available in the UK through NHS specialist services or private prescribing.
What are the main differences between Wegovy and Mounjaro?
Wegovy (semaglutide) is a GLP-1 only medication with an average weight loss of approximately 15% body weight. Mounjaro (tirzepatide) is a dual GIP/GLP-1 medication with average weight loss of 15–21% depending on dose. Both are once-weekly injections requiring clinical assessment before prescription.
How do I check if I'm eligible for prescription weight loss medication in the UK?
Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Use our free BMI calculator on this page to check your current BMI, then consult your GP or a licensed prescriber for personalised assessment.
What's the difference between Ozempic and Wegovy?
Both contain semaglutide, but Ozempic is licensed for type 2 diabetes (doses up to 2 mg), while Wegovy is specifically licensed for weight management in the UK (up to 2.4 mg). Wegovy is the correct prescription for weight loss; using Ozempic for weight loss is off-label.
Can I get weight loss medication through the NHS?
Yes, through tier 3 specialist weight management services following a GP referral. However, NHS availability varies significantly by region and waiting lists can be very long. Private online prescribing offers faster access without NHS referral — a UK-licensed prescriber will assess your eligibility based on your BMI and individual health.
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.