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
Weight Loss After Pregnancy — UK Medication Options
Many women find weight management challenging after pregnancy. The good news is that prescription weight loss medication is now available in the UK for eligible adults, including those managing postpartum weight. This guide explains your options through the NHS and private routes, how to check eligibility, and what to expect. We've also included our free BMI calculator and GLP-1 weight loss calculator to help you understand where you stand and what medication might mean for your weight management journey.
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-Licensed Prescription Weight Loss Options
Three prescription-only medications are licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All three work by mimicking natural hunger-regulating hormones. Mounjaro and Wegovy are injected once weekly, while Saxenda is a daily injection. Clinical trials show these medications help users lose an average of 15–21% of their body weight when combined with a reduced-calorie diet and physical activity—though individual results vary significantly. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions like high blood pressure or type 2 diabetes. Your GP or a licensed prescriber will assess whether prescription weight loss medication is suitable for your individual circumstances.
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 in the UK
NHS route: Request a referral from your GP to your local tier 3 specialist weight management service. Availability and waiting times vary significantly by region. Private route: Online consultation with a UK-licensed prescriber, followed by prescription dispensing through a GPhC-registered pharmacy if approved. Private access is faster and doesn't require an NHS referral, though there is a cost (typically £129–£320 per month depending on dose). Either way, a clinical assessment is mandatory—no medication is prescribed without one. Use our free BMI calculator above to understand your starting point, and try our GLP-1 weight loss calculator to explore potential outcomes at different doses.
- 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 weight loss medication while breastfeeding?
No. These medications are not recommended during breastfeeding as safety data is limited. If breastfeeding is important to you, discuss timing options with your GP or healthcare provider. Some women wait until breastfeeding ends before starting medication.
How long after pregnancy can I start prescription weight loss medication?
There's no strict timeline, but most healthcare providers suggest waiting until postpartum recovery is complete (typically 6–8 weeks) and any postpartum complications have resolved. Discuss timing with your GP or prescriber based on your individual recovery.
What if my BMI is below 30—am I ineligible?
Not necessarily. If you have a BMI of 27–29.9 and a weight-related health condition (like gestational diabetes history, high blood pressure, or sleep apnoea), you may still be eligible. A clinical assessment will determine this.
Will weight loss medication work faster than diet and exercise alone?
Clinical evidence shows medication helps achieve greater weight loss when combined with a reduced-calorie diet and increased physical activity. Medication is a tool to support lifestyle changes, not a replacement for them. Results vary between individuals.
How do I know if I'm eligible without seeing my GP first?
Use our free BMI calculator on this page to check where your weight falls. If your BMI is 30 or above, or 27–29.9 with known health conditions, you likely meet basic criteria—but a prescriber must assess your full health picture before prescribing.
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.