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
Postpartum Weight Loss: A Safe, Realistic UK Guide
Many women find that weight loss after pregnancy is gradual and takes time—especially if breastfeeding. The NHS recommends a cautious approach to postpartum weight management, as gradual weight management can affect milk supply and energy levels during this demanding period. This guide covers safe, realistic strategies for postpartum weight loss in the UK, from nutrition to when prescription weight management might be considered, alongside timing expectations and GP support options.
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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.
Safe Weight Loss After Pregnancy: What the NHS Recommends
Postpartum weight loss is not the same as standard weight management—your body has undergone significant changes. The NHS advises that sustainable weight loss in the postpartum period should be gentle and gradual, typically around 0.5 kg per week. If breastfeeding, calorie restriction must be cautious: too large a deficit can reduce milk supply and leave you depleted during an already exhausting time.
- Breastfeeding typically burns 300–500 kcal daily, which aids natural weight reduction over several months
- Most women lose approximately 5–8 kg in the first six weeks postpartum (baby, placenta, fluids)
- Remaining weight loss should be gradual over 6–12 months, not rushed
- Pelvic floor exercises and gentle movement are important before intensive exercise
Use our free BMI calculator to track your current BMI and understand your personal healthy weight range as you progress.
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.
Weight Loss Medication and Postpartum Support
Prescription weight loss medication is not recommended during pregnancy or breastfeeding. However, once you have stopped breastfeeding and have clearance from your GP (typically at least 6 months postpartum), weight management options may become available. Medications like GLP-1 weight loss injections may be considered if you have a BMI over 30 or 27–29.9 with weight-related health conditions, following a clinical assessment.
Your GP can discuss whether prescription weight management, alongside lifestyle changes, is suitable for your individual situation. Our free GLP-1 weight loss calculator can help you understand potential outcomes if medication becomes an option later. Always prioritise recovery, nutrition, and mental health during the postpartum period—weight loss is secondary to your wellbeing.
- 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 long does postpartum weight loss usually take?
Most women lose approximately 5–8 kg naturally in the first six weeks postpartum. Remaining weight typically requires 6–12 months of gradual loss at 0.5 kg per week. Breastfeeding accelerates this process by burning 300–500 kcal daily. Individual timelines vary based on pregnancy weight gain, activity level, and diet.
Is it safe to diet while breastfeeding?
Yes, but carefully. The NHS recommends a gentle approach: aim for no more than 0.5 kg per week loss and avoid very low-calorie diets. Severe calorie restriction can reduce milk supply and leave you exhausted. Focus on nutrient-dense foods, adequate hydration, and gradual activity increases rather than restriction.
When can I consider prescription weight loss medication after pregnancy?
Most prescribers recommend waiting until you have stopped breastfeeding—typically at least 6 months postpartum—and have clearance from your GP. Prescription weight loss medications are not recommended during pregnancy or breastfeeding. A clinical assessment will determine eligibility based on your BMI and health factors.
What is the safest exercise to do postpartum?
Start gently with pelvic floor exercises (essential after birth) and walking in the first 6–8 weeks. Avoid high-impact exercise until you've been cleared by your GP or a women's health physiotherapist, typically 12+ weeks postpartum. Gradually increase intensity once your core and pelvic floor are stronger.
Should I aim to return to my pre-pregnancy weight?
Not necessarily. Your body may have naturally shifted—some women's weight distributes differently after pregnancy. Focus on reaching a healthy BMI rather than a specific pre-pregnancy weight. Use our free BMI calculator to understand your personal healthy weight range, then work towards that with your GP or a dietitian.
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.