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
Post Pregnancy Weight Loss Plan: Safe, Evidence-Based Guidance
Losing weight after pregnancy is a common goal for many UK mums, but it's important to approach it safely — especially if you're breastfeeding. Most women lose around 5–7 kg immediately after birth, with gradual weight loss continuing over 6–12 months as your body recovers. This guide covers safe, evidence-based approaches to postpartum weight management, NHS support available, and when prescription weight loss medication might be considered after specialist assessment. The key is patience, realistic expectations, and personalised medical guidance from your GP.
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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 Postpartum Weight Loss: Timing and Approaches
The first 6 weeks postpartum is about recovery, not weight loss. Your body needs time to heal, hormones to stabilise, and energy for caring for your newborn — and especially for milk supply if breastfeeding. The NHS recommends waiting until 6–8 weeks after delivery (or 12 weeks if you had a caesarean) before starting active weight loss efforts.
Safe postpartum weight loss approaches include:
- Breastfeeding (if you choose to) — burns approximately 300–500 calories daily and naturally supports gradual weight loss
- Balanced nutrition — focus on nutrient-dense foods, not calorie restriction, especially when breastfeeding
- Gradual physical activity — start with walking, pelvic floor exercises, then strength work as cleared by your GP or physiotherapist
- Aim for 0.5–1 kg per week loss — this is sustainable and safe while breastfeeding
- Stay hydrated — drinking enough water supports metabolism and milk supply
Calculate your personal healthy weight range using our free BMI calculator to set realistic postpartum goals based on your height and body composition.
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.
NHS Support and When to Consider Medical Options
Your GP can provide personalised postpartum weight management support through NHS tier 1 and 2 services, including digital weight loss programmes and behaviour change support. If you have a BMI of 30 or above (or 27+ with weight-related health conditions like gestational diabetes), you may be eligible for referral to specialist weight management services after your recovery period.
Prescription weight loss medication, including GLP-1 weight loss injections, is not typically started until 6–12 months postpartum and requires specialist assessment. These medications are prescription-only and require clinical evaluation. Track your progress with our free progress tracker and discuss any medical options with your GP, who can assess what's right for your individual situation.
- 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 after pregnancy can I start losing weight?
You should focus on recovery for the first 6–8 weeks (12 weeks after caesarean). Gentle activity like walking can start earlier if you feel ready. Active weight loss efforts typically begin after your postpartum GP check (usually 6 weeks). Breastfeeding (if you choose to) naturally supports gradual weight loss without intentional dieting.
Is it safe to diet while breastfeeding?
Yes, but carefully. Avoid very low calorie diets or gradual weight management, which can reduce milk supply. A moderate deficit of 300–500 calories daily is generally safe. Focus on nutrient-dense foods rather than severe calorie restriction. Always discuss your plan with your GP or a registered dietitian, especially if you're breastfeeding.
What's a realistic postpartum weight loss timeline?
Most women lose 5–7 kg immediately after birth. Continued gradual loss (0.5–1 kg weekly) over 6–12 months is normal and safe. The remaining weight may take 12–24 months to shift, particularly if breastfeeding. Weight loss varies based on genetics, activity level, diet, and whether you're breastfeeding.
Can I use prescription weight loss medication after pregnancy?
Prescription weight loss medications are not started immediately postpartum. They're typically considered 6–12 months after delivery, following specialist assessment. GLP-1 medications like Wegovy are prescription-only and only available after clinical evaluation by a qualified prescriber or specialist service.
How can I check if I'm at a healthy postpartum weight?
Use our free BMI calculator to determine your healthy weight range for your height. A healthy BMI is 18.5–24.9 for most adults (lower thresholds apply for some ethnic groups). Your GP can provide personalised guidance based on your medical history, pre-pregnancy weight, and overall health — not just numbers on a scale. ```
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.