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
Best Vegan Weight Loss Medication in the UK
If you follow a vegan diet and are looking for weight management support, prescription medication options are available in the UK for eligible adults. Unlike some weight loss approaches, modern GLP-1 medications can be used alongside a vegan lifestyle. This guide covers the prescription weight loss options available, who qualifies, and how to access them through the NHS or privately. Whether you're interested in weight management uk through medication or want to understand your options, we'll explain what's available and what the evidence shows.
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 Prescription Weight Loss Options for Vegan Adults
Three GLP-1 medications are currently licensed in the UK for weight management in adults: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All three can be used alongside a vegan diet with proper nutritional planning.
Mounjaro is a once-weekly injection containing tirzepatide, a dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks alongside reduced-calorie intake and increased activity. Wegovy (semaglutide) is also once-weekly and delivered average weight loss of approximately 15% in trials. Saxenda (liraglutide) is a daily injection with an average weight loss of around 5–8%.
Eligibility requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Your prescriber will assess suitability based on your individual health profile, including nutritional status important for vegan diets.
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.
Accessing Weight Loss Medication: NHS vs Private
NHS access: Prescription weight loss medication is available through specialist tier 3 weight management services, typically accessed via GP referral. However, availability and waiting times vary significantly by region. Some areas have limited capacity, with waiting lists extending several months or longer.
Private access: You can obtain a prescription through GPhC-registered online prescribing services following a clinical assessment with a UK-licensed prescriber. This route does not require NHS referral and is typically faster, though there is a cost. A prescriber will assess your medical history, BMI, weight-related health conditions, and nutritional considerations relevant to vegan diets.
Whatever your route, use our free BMI calculator and GLP-1 weight loss calculator to understand your starting point and explore potential outcomes. Start a conversation with your GP about whether prescription weight management is right for you.
- 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 take Mounjaro or Wegovy on a vegan diet?
Yes, both medications can be used alongside a vegan diet. However, because GLP-1 medications reduce appetite, ensuring adequate protein and micronutrient intake becomes especially important. Work with a vegan nutritionist or dietitian to maintain balanced nutrition while using weight loss medication, particularly for B12, iron, zinc, and omega-3 intake.
How quickly will I lose weight on prescription weight loss medication?
Clinical trials show average weight loss of 15–21% over approximately 18 months, though individual results vary significantly. The NHS recommends losing weight at a rate of 0.5–1 kg per week for sustainable results. Weight loss medication works best alongside reduced-calorie nutrition and increased physical activity.
What are the side effects of GLP-1 weight loss injections?
Common side effects include nausea, diarrhoea, constipation, and stomach pain, typically most noticeable when starting or increasing doses. These often improve over time. Serious side effects are rare but can include severe stomach pain (possible pancreatitis) or gallbladder problems. Always report concerns to your prescriber.
How do I check if I'm eligible for prescription weight loss medication?
You're typically eligible if you have a BMI of 30 or above, or 27 or above with weight-related health conditions. Use our free BMI calculator to check your BMI instantly. Then speak to your GP about referral to specialist weight management services, or contact a private prescriber for an assessment.
Is Mounjaro or Wegovy covered by the NHS?
Yes, both Mounjaro and Wegovy are available through NHS specialist weight management services (tier 3), though availability varies by region. Your GP can refer you, but waiting lists can be lengthy in many areas. Private prescribing offers faster access if you can afford the cost.
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.