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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Semaglutide Weight Loss Dosage Chart — UK Costs & How to Access
Semaglutide is a prescription-only weight loss injection available in the UK under the brand name Wegovy. The standard semaglutide 2.4mg dose is administered once weekly and represents the maximum maintenance dose used in clinical trials. If you're considering semaglutide weight loss treatment, understanding the dosage escalation schedule, where you can access it, and what it costs is essential. This guide covers the complete dosage chart in millilitres, UK pricing, and how to get semaglutide through either NHS specialist services or private prescribing.
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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 Cost, Access Routes & What to Expect
Wegovy (semaglutide) is available in the UK through two main routes:
- NHS specialist services: Referred through your GP to a tier 3 or tier 4 weight management service. Free on prescription but availability varies significantly by region (Integrated Care Board). Waiting lists can be lengthy—often 6–18 months in many areas.
- Private route: Online consultation with a UK-licensed prescriber. If approved, your prescription is dispensed by a GPhC-registered pharmacy. Costs typically range from £120–£280 per month depending on dose and provider. Monthly supply (4 weeks) covers a single 0.5ml to 2.4mg injection per week.
Most private providers offer a stepped payment plan matching the dosage escalation schedule (weeks 1–4 at 0.25mg, weeks 5–8 at 0.5mg, and so on). The semaglutide 2.4mg dose—the maximum strength—is usually reached by week 17 of treatment and costs approximately £220–£280 monthly for ongoing prescriptions.
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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.
NHS vs Private: Pathway & Timeline
NHS route: Requires GP referral to a specialist weight management service. You'll be assessed for eligibility (typically BMI ≥30 or BMI ≥27 with weight-related health conditions). If approved, you receive fortnightly or monthly clinical support and blood tests at no additional cost. However, regional variation means some areas have limited availability or very long waits.
Private route: Faster access—most approvals within 48–72 hours of online consultation. You answer a health questionnaire, have a video or telephone consultation with a UK prescriber, and if suitable, receive your prescription immediately. You'll manage your own dosage escalation and report any concerns to your prescriber. Use our free GLP-1 weight loss calculator above to explore projected weight loss outcomes at different doses before committing.
- 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.
What is the semaglutide dosage in millilitres for each week?
Wegovy pens are dosed by strength, not millilitres. Each pen delivers 0.25mg, 0.5mg, 1mg, 1.7mg, or 2.4mg per weekly injection. A standard pen contains 1.5ml of solution. Doses escalate every 4 weeks: start 0.25mg (weeks 1–4), increase to 0.5mg (weeks 5–8), 1mg (weeks 9–12), 1.7mg (weeks 13–16), then 2.4mg (week 17 onwards). Clinical trials show the 2.4mg dose produces the most significant weight loss—approximately 15% body weight on average.
How much does Wegovy cost on the NHS in the UK?
Wegovy is free on NHS prescription if you're prescribed through a specialist weight management service after referral from your GP. However, NHS availability varies by region, and waiting lists are often very long (6–18 months in many areas). Not all ICBs (Integrated Care Boards) currently fund semaglutide, so access depends where you live. Your GP can confirm availability in your area.
What's the typical private cost for semaglutide in the UK per month?
Private Wegovy typically costs £120–£160 per month at lower doses (0.25mg–0.5mg), rising to £220–£280 monthly at the 2.4mg maintenance dose. Most private providers offer stepped pricing matching your dosage schedule, so you pay less during the initial weeks and more once you reach maintenance. Costs vary between providers, so it's worth comparing prices before starting an online consultation.
How do I access semaglutide privately online in the UK?
Search for a GPhC-registered online prescribing service. Complete a brief health questionnaire covering medical history, medications, and weight loss goals. Arrange a video or phone consultation with a UK-licensed prescriber (usually within 24–48 hours). If approved, your prescription is sent to a GPhC-registered pharmacy, and your first dose is delivered within 3–5 working days. Try our BMI calculator above to confirm your eligibility (typically BMI ≥27 with health conditions or BMI ≥30).
Is semaglutide weight loss different from Ozempic?
Both contain semaglutide, but Ozempic is licensed for type 2 diabetes at doses up to 2mg—not for weight loss in the UK. Wegovy is the licensed weight loss version, approved up to 2.4mg. Using Ozempic for weight loss is off-label and not recommended. A prescriber will assess you for Wegovy specifically as a weight loss treatment, ensuring you receive the correct licensed medication and appropriate monitoring for your situation.
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.