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
Wegovy and Pregnancy — What You Need to Know
Wegovy (semaglutide) is not recommended during pregnancy and should be stopped if you become pregnant. If you're considering weight management treatment and planning to conceive, it's important to understand the UK access routes, costs, and how pregnancy changes your eligibility. This guide covers NHS and private options for Wegovy prescriptions in the UK, and what to expect when seeking professional advice about weight management during your reproductive years.
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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.
UK Private Prescription Costs and Access Routes
In the UK, Wegovy is a prescription-only medicine available through two main routes: NHS specialist services and private prescribers. On the NHS, access is typically through tier 3 specialist weight management services following a GP referral, though availability and waiting times vary significantly by region and integrated care board (ICB). Private prescriptions cost between approximately £129 and £280 per month depending on the dose, with costs increasing as you progress through the GLP-1 receptor agonist titration schedule. A private consultation fee (typically £30–£50) is usually charged separately, though some providers include this in the first month's cost. Private prescriptions are issued by UK-licensed prescribers following an online clinical assessment, without requiring NHS referral. Each pre-filled pen contains 4 doses (4 weeks' supply), so monthly costs represent a single pen per month at lower doses, though higher doses may require additional pens.
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.
Pregnancy, Eligibility, and NHS Versus Private Routes
Wegovy must be stopped at least 4 weeks before trying to conceive and is contraindicated in pregnancy. If you're planning pregnancy, discuss timing with your prescriber before starting treatment. On the NHS, you'll need a GP referral to a specialist weight management service; this route is free but involves potential waiting lists and regional availability issues. The NHS NICE guidance supports tirzepatide (Mounjaro) and semaglutide (Wegovy) for weight management in eligible adults with BMI ≥30 or ≥27 with comorbidities. For private access, you can arrange an online consultation directly without NHS involvement—faster but at personal cost. Your prescriber will assess whether Wegovy is appropriate for you, considering your health profile, contraception use, and pregnancy plans. If you're on an oral contraceptive, you'll need to add a barrier method for 4 weeks after starting and after each dose increase, as Wegovy may reduce oral medication absorption.
- 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 Wegovy if I'm trying to get pregnant?
No. Wegovy must be stopped at least 4 weeks before attempting to conceive. If you're planning pregnancy, discuss timing with your prescriber before starting treatment. Your prescriber will assess whether this medicine is suitable for you based on your reproductive plans.
How much does a private Wegovy prescription cost per month in the UK?
Private Wegovy typically costs £129–£280 per month depending on your dose. Initial consultation fees (£30–£50) apply separately at most providers. Costs increase as you progress through the dose escalation schedule from 0.25mg to 2.4mg over approximately 16 weeks.
Can I get Wegovy on the NHS in the UK?
Yes, through specialist tier 3 weight management services following a GP referral. NHS access is free but availability varies by region and waiting times can be significant. Your GP can assess your eligibility and arrange a referral if appropriate.
What contraception should I use if I'm taking Wegovy?
If you take oral contraceptives, you must add a barrier method or switch to non-oral contraception for 4 weeks after starting Wegovy and 4 weeks after each dose increase. This is because Wegovy may reduce how well oral medications are absorbed. Discuss options with your prescriber.
How do I access a private Wegovy prescription in the UK?
Arrange an online consultation with a UK-licensed prescriber through a GPhC-registered pharmacy. You'll complete a health questionnaire, have a brief video or written assessment, and if approved, receive a prescription for dispensing. The process typically takes 24–48 hours from consultation to delivery.
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.