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
Ozempic Weight Loss Results After 1 Month
Many people search for Ozempic weight loss results after 1 month, but it's important to clarify that Ozempic is not licensed for weight loss in the UK. Ozempic (semaglutide) is approved for type 2 diabetes management only. For weight management, the licensed UK medicine is Wegovy, which contains the same active ingredient at a higher dose. This guide explains what semaglutide can actually achieve for weight loss, realistic timelines, and how the NHS and prescription weight loss medication work in the UK.
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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.
Semaglutide for Weight Loss: What the Evidence Shows
Semaglutide (the active ingredient in both Ozempic and Wegovy) is a GLP-1 receptor agonist that works by reducing appetite and helping you feel fuller after eating. In clinical trials, semaglutide helped participants lose significant weight — but results in month one are typically modest.
- Week 1–4: Most people experience mild appetite suppression and may lose 1–2 kg, though some notice no change yet
- Why slow start: The first dose (0.25 mg for Wegovy) is very low — it's designed for tolerability, not maximum effect
- Nausea is common: Many people report feeling sick initially, which itself can reduce appetite
- Individual variation: Some people see faster results; others take weeks to notice change
The NHS recommends losing weight at a rate of 0.5–1 kg per week for sustainable results. A 1–2 kg loss in month one aligns with this guidance and reflects the medication working safely.
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.
Realistic Weight Loss Timeline and Dose Escalation
Semaglutide weight loss is not immediate because the medication requires dose escalation. Wegovy starts at 0.25 mg weekly and increases every 4 weeks: 0.5 mg (week 5), 1 mg (week 9), 1.7 mg (week 13), and 2.4 mg (week 17+). Significant weight loss typically begins after 8–12 weeks when you reach a therapeutic dose.
Clinical trial data (STEP-1) showed that after 68 weeks at the maximum dose, participants lost an average of approximately 15% of body weight when combining semaglutide with a reduced-calorie diet and increased physical activity. Calculate your potential weight loss outcomes using our free GLP-1 weight loss calculator.
For comparison, check your current BMI using our free BMI calculator to understand your starting point and realistic health targets.
- 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 Ozempic licensed for weight loss in the UK?
No. Ozempic is licensed only for type 2 diabetes management in the UK. Wegovy is the licensed weight loss version of semaglutide. Using Ozempic for weight loss would be off-label prescribing. Always use medications only as prescribed and licensed.
How much weight can I realistically lose in month one on semaglutide?
Most people lose 1–2 kg in the first month because the starting dose (0.25 mg) is very low for tolerability. Significant weight loss typically begins after 8–12 weeks as the dose increases. Individual results vary based on diet, activity, and metabolism.
What's the difference between Ozempic and Wegovy?
Both contain semaglutide, but Ozempic doses go up to 2 mg (approved for diabetes). Wegovy doses go up to 2.4 mg and is licensed specifically for weight management. Wegovy is the appropriate choice for weight loss treatment in the UK.
How do I access semaglutide for weight loss in the UK?
You can access Wegovy through NHS specialist weight management services (via GP referral) or through private online prescribing following a clinical assessment with a UK-licensed prescriber. Access varies by region. Always ensure any prescription comes from a qualified healthcare professional.
Why is weight loss slow in the first month?
The starting dose is deliberately low to minimize side effects like nausea and stomach upset. The medication works best once you reach a higher therapeutic dose (usually by week 9–17). This graduated approach helps your body adapt and supports sustainable, safer weight loss.
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.