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
Will My Hair Grow Back After Mounjaro?
Hair loss is a known side effect of Mounjaro (tirzepatide), but the good news is that it's typically temporary and reversible. In most cases, hair regrowth begins within a few months of stopping the medication or after your body has adjusted to it. This guide explains what causes hair loss on Mounjaro, how long it usually lasts, and when you should speak to your GP about this side effect.
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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.
Understanding Hair Loss on Mounjaro
Hair loss on Mounjaro (tirzepatide) is classified as a common side effect, affecting up to 1 in 10 people. This type of hair loss is typically telogen effluvium — a temporary condition where hair prematurely enters the shedding phase. The underlying mechanisms include gradual weight management itself, nutritional shifts as your appetite decreases, and hormonal changes triggered by the medication's effects on hunger and metabolism. Unlike permanent conditions such as male pattern baldness, telogen effluvium is reversible. Most people experience hair regrowth within 3–6 months of stopping Mounjaro or once their body has fully adapted to the medication. Some users report improvement while still taking the injection, as the hair shedding stabilises after the initial months.
- Affects approximately 1 in 10 people on Mounjaro
- Usually temporary and reversible
- Often linked to gradual weight management and metabolic changes
- Regrowth typically begins 3–6 months after stopping or adjusting
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.
Managing Hair Loss While on Mounjaro
If you're experiencing noticeable hair loss on Mounjaro, there are practical steps to support recovery. Ensure you're meeting your nutritional needs, particularly protein, iron, zinc, and biotin — gradual weight management can deplete these essential nutrients. Speak to your GP or a registered dietitian about supplementation if appropriate. Avoid excessive styling stress and harsh treatments. Keep a record of when hair loss started and whether it's improving, then discuss this with your prescriber at your next review. For many people, continuing Mounjaro alongside nutritional support leads to natural regrowth within months. If hair loss is severe or causes significant distress, your prescriber may adjust your dose, pause treatment temporarily, or discuss switching to another weight management option such as Wegovy (semaglutide).
- 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 hair loss last on Mounjaro?
Hair loss typically appears within the first few weeks to months of starting Mounjaro and usually lasts 3–6 months total. Once you stop the medication or your body adjusts, hair regrowth typically begins within 3–6 months. Individual timelines vary — some people see improvement while still taking the injection.
Is hair loss on Mounjaro permanent?
No. Hair loss from Mounjaro is temporary and reversible. The hair loss is usually telogen effluvium, triggered by gradual weight management and metabolic changes, not by permanent damage to hair follicles. Your hair should regrow once the trigger is removed or your body adapts.
Can I prevent hair loss while taking Mounjaro?
You can't eliminate the risk entirely, but adequate nutrition helps. Maintain sufficient protein intake, and consider supplementing iron, zinc, and biotin if deficient — gradual weight management can deplete these. Speak to your GP or dietitian about personalised nutritional support.
Should I stop Mounjaro because of hair loss?
Not necessarily. Hair loss is often temporary, and many people experience regrowth while continuing the medication. Speak to your GP or prescriber before making changes. They can discuss whether continuing, pausing, or switching to an alternative like Wegovy is best for you.
Is hair loss on Mounjaro different from hair loss on other weight loss injections?
Hair loss has been reported with GLP-1 medications like Wegovy and with Mounjaro. It appears to be linked more to gradual weight management itself than to the specific medication. Use our GLP-1 weight loss calculator to explore realistic timelines and discuss side effect profiles with your prescriber.
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.