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
How Progesterone Affects Weight Loss
Progesterone is a hormone that plays a significant role in weight management, particularly for women. Changes in progesterone levels throughout the menstrual cycle, during pregnancy, and at menopause can influence appetite, metabolism, and where your body stores fat. Understanding how progesterone affects weight loss can help you approach weight management more effectively. If you're struggling with weight despite healthy habits, hormonal factors like progesterone may be part of the picture. Your GP can assess whether hormone-related issues are affecting your weight.
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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.
How Progesterone Influences Weight and Metabolism
Progesterone affects weight through several mechanisms:
- Appetite regulation: Progesterone can increase appetite, particularly during the luteal phase of the menstrual cycle (after ovulation). This may lead to increased food intake and cravings for carbohydrate-rich foods.
- Metabolic changes: Progesterone may slightly increase metabolic rate, but this effect is modest and varies between individuals. Some research suggests it promotes fat storage, particularly around the abdomen.
- Fluid retention: Higher progesterone levels can increase water retention, leading to weight fluctuations that aren't related to fat loss.
- Insulin sensitivity: Progesterone may reduce insulin sensitivity during certain phases of the menstrual cycle, affecting blood sugar regulation and fat storage.
For women using the combined contraceptive pill or HRT, progesterone-containing formulations may influence weight management. Tracking your weight loss using our free progress tracker can help you identify patterns related to your cycle.
Clinically BackedWeight Loss
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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 Strategies Considering Progesterone Levels
If progesterone fluctuations are affecting your weight loss efforts, consider these evidence-based approaches:
- Track your cycle: Monitor how your appetite and energy change throughout your menstrual cycle to time your fitness efforts and nutrition accordingly.
- Adjust nutrition strategically: During high-progesterone phases (luteal phase), focus on protein and healthy fats to manage increased appetite.
- Stay consistent: Sustainable weight management requires consistent effort across all cycle phases, not just low-progesterone weeks.
- Seek professional guidance: Your GP or a registered dietitian can provide personalised advice if hormonal imbalances are hindering your weight loss efforts.
Use our free BMI calculator to establish your baseline and track progress. For prescription weight loss medication through NHS weight management services, speak with your GP about referral options.
- 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.
Does progesterone make you gain weight?
Progesterone doesn't directly cause permanent weight gain, but it can increase appetite, promote water retention, and influence where your body stores fat. These effects vary between individuals and across different phases of the menstrual cycle. Most weight changes related to progesterone are temporary fluctuations rather than permanent fat gain.
Will weight loss be harder during the luteal phase?
The luteal phase (after ovulation) typically has higher progesterone levels, which may increase appetite and slightly reduce metabolic rate. Weight loss may appear slower during this phase, but this is often due to increased water retention and appetite rather than actual fat loss. Consistency across all cycle phases supports sustainable weight management.
Can progesterone from contraceptives affect weight loss?
Yes, progesterone-containing contraceptives can influence weight management. The combined pill and some hormonal IUDs contain synthetic progesterone, which may increase appetite or water retention in some women. Discuss with your GP if hormonal contraception is affecting your weight loss efforts—alternative options may be available.
Does menopause progesterone drop affect weight?
Yes, progesterone drops significantly during menopause, but oestrogen also declines. This hormonal shift often leads to weight gain and changes in metabolism. Menopause weight gain is common and multifactorial. Your GP can discuss HRT options and weight management strategies tailored to menopause.
Should I use weight loss medication if hormones affect my weight?
If hormonal factors are significantly impacting weight management, your GP can assess whether prescription weight loss medication alongside lifestyle changes might help. Prescription weight loss options are available through NHS weight management services for those meeting eligibility criteria, particularly if weight-related health conditions are present.
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.