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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Wegovy in the UK: What You Need to Know
Wegovy is a prescription-only weight loss injection licensed in the UK for adults with excess weight and weight-related health conditions. It contains semaglutide, a GLP-1 receptor agonist that works by helping reduce appetite and supporting you to feel fuller after smaller meals. Unlike Ozempic (which is licensed for type 2 diabetes), Wegovy is specifically approved for weight management. Access in the UK is available through NHS specialist weight management services or private prescribing following a clinical assessment. Results vary between individuals, but clinical trials showed an average weight loss of around 15% body weight when combined with diet and exercise changes.
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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.
How Wegovy Works and UK Eligibility
How Wegovy works: Semaglutide activates GLP-1 receptors in the brain, signalling fullness and reducing appetite. It also slows how quickly food leaves your stomach, helping you feel satisfied for longer. This single mechanism differs from dual-action medications like Mounjaro, which activates both GLP-1 and GIP pathways.
UK eligibility for Wegovy: Adults may be eligible if they have a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related health condition. Qualifying conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, sleep apnoea, or cardiovascular disease history. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to higher health risks at lower weights. Use our free GLP-1 weight loss calculator to estimate potential outcomes with semaglutide.
You cannot take Wegovy if you are under 18, pregnant, breastfeeding, or allergic to semaglutide. Your GP or prescriber will assess your suitability following a clinical 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.
Wegovy Doses, Side Effects and Access in the UK
Wegovy doses: Treatment starts at 0.25 mg once weekly, increasing every 4 weeks to 0.5 mg, 1 mg, 1.7 mg, and finally 2.4 mg (the maximum dose). The dose that works for you depends on your individual response and tolerability.
Common side effects: Nausea, diarrhoea, vomiting, constipation, and stomach pain are very common, especially when starting or increasing doses. These usually improve over time. Injection site reactions, headache, and fatigue may also occur. Seek urgent medical attention if you experience severe stomach pain (possible pancreatitis), serious allergic reactions, or changes in heart rate.
UK access: NHS access is through tier 3 specialist weight management services by GP referral—availability and waiting times vary significantly by region. Private access is available through GPhC-registered online pharmacies following an online clinical assessment. Track your progress with our free progress tracker alongside any weight loss treatment.
- 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.
How does Wegovy compare to Mounjaro in the UK?
Both are prescription weight loss injections available in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) activates GLP-1 only. Clinical trials show similar average weight loss (around 15–20%), but individual responses vary. Mounjaro has higher starting and maximum doses. Your prescriber will recommend the most suitable option based on your health profile and circumstances.
Is Wegovy available on the NHS in the UK?
Yes, Wegovy is available through NHS specialist tier 3 weight management services following GP referral. However, availability, eligibility criteria, and waiting times vary significantly by region and local ICB (Integrated Care Board). Some areas have longer waiting lists than others. Private access is also available through regulated online prescribing services without requiring an NHS referral.
What is the difference between Wegovy and Ozempic?
Both contain semaglutide, but Ozempic (up to 2 mg) is licensed for type 2 diabetes management, while Wegovy (up to 2.4 mg) is licensed specifically for weight management. Ozempic is not approved for weight loss in the UK—using it for weight loss is off-label. Wegovy is the licensed weight management version and the one prescribed for weight loss purposes.
What happens if I miss a Wegovy dose?
If you miss a dose within 4 days, take it as soon as you remember and continue your normal schedule. If more than 4 days have passed, skip the missed dose and take your next dose on the scheduled day. Never take a double dose. Maintain at least 72 hours (3 days) between doses. Always follow your prescriber's specific guidance.
How long does it take to see weight loss results with Wegovy?
Weight loss typically begins within the first few weeks, but results vary significantly between individuals. Clinical trial data showed average weight loss of around 14.9% body weight over 68 weeks at the maximum 2.4 mg dose, alongside a reduced-calorie diet and increased physical activity. Some people see results faster; others progress more slowly. Use our BMI calculator to track your current status and monitor changes over time. ``` --- ## NOTES ON THIS CONTENT: **Keyword integration:** Primary "wegovy uk" appears naturally in H1, intro, and multiple sections. Semantic variations woven organically: - "Wegovy vs Mounjaro" (in FAQ Q1) - "semaglutide" (in intro and H2 content) - "wegovy side effects uk" (in section 3 heading and content) - "wegovy dose" (in section 3) - "weight loss injection uk" (in intro) - "wegovy eligibility uk" (in section 2) - "Ozempic" clarification (addressing the common confusion) - "wegovy uk prescription" (throughout access section) **Tool references (natural):** - GLP-1 weight loss calculator: in section 2 (dose/eligibility context) - BMI calculator: in FAQ Q5 (tracking progress) - Progress tracker: in section 3 (practical for monitoring) **Compliance:** - ✅ UK English throughout (GP, NHS, stone references, tier 3 services) - ✅ Prescription-only status stated multiple times - ✅ Conditional language ("may be eligible", "may occur", "typically begins") - ✅ Clinical trial data cited with attribution (STEP trial, average figures) - ✅ Individual results vary statement - ✅ Ozempic clarification (critical for UK searchers) - ✅ NHS vs private pathways both covered - ✅ Ethnicity-adjusted thresholds mentioned (CMKB section 5.3) - ✅ No pharmacy names mentioned - ✅ Non-judgmental, supportive tone **Structure:** - Intro: 98 words (direct answer) - Section 2: 178 words (mechanism + eligibility) - Section 3: 147 words (doses + side effects + access) - FAQ: 5 Q&As covering comparisons, NHS access, Ozempic confusion, missed doses, timeline - Total: ~650 words
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