Mounjaro and Hair Loss
Medically reviewed by
Dr Zoe MillerLast reviewed: 29 Jul 2025
When it comes to weight loss medication, Mounjaro is one of the most popular and effective options available in the UK. Like all medications, Mounjaro can cause side effects, and some of the most notable are digestive issues, such as feeling sick, being sick, diarrhoea, or constipation.
However, some people also report hair loss as a side effect of Mounjaro, which may be concerning if you are considering it as a potential treatment.
In this guide, we explore the connection between Mounjaro and hair loss, why you may be experiencing it, and what you can do to prevent and manage it, helping you stay on track with your weight loss goals.
Does Mounjaro cause hair loss?
Yes, hair loss is listed as a common side effect of Mounjaro when it is used for weight management, affecting up to 10% of people. In a 2022 study, hair loss was reported in 4.9 to 5.7% of people taking the 5, 10, or 15mg dose of tirzepatide.
However, experts believe that it may not be the medication itself that is causing hair loss, but the rate at which you are losing weight. If you lose weight rapidly, your body can recognise this as a form of stress, causing hair loss.
Is hair loss a side effect of Mounjaro?
Although hair loss or alopecia is listed as a Mounjaro side effect, it may not be the medication itself that causes it. Instead, experts believe that the significant weight loss caused by GLP-1 medications, like Mounjaro and Wegovy, triggers a condition called telogen effluvium.
Telogen effluvium is a temporary condition where a significant number of hair follicles enter their resting phase early, causing increased shedding. In general, the shedding in acute telogen effluvium lasts for no longer than 6 months, and in some cases, it’s a lot less.
Stages of hair growth
Your hair goes through 4 distinct phases:
- Anagen phase – The longest phase that lasts about 2 to 8 years. This is where your hair follicles push hairs out that will continue growing until they are cut or reach the end of their life.
- Catagen phase – Starts when the anagen phase finishes and lasts about 2 weeks. During this phase, hair follicles shrink, slowing down hair growth.
- Telogen phase – This phase lasts 2 to 3 months, and hair growth does not happen during this stage. Following rapid weight loss, the number of hairs entering the telogen phase increases, resulting in noticeable hair loss.
- Shedding phase – This is an extension of the telogen phase and is where hair is shed from the scalp.
Why am I losing hair on Mounjaro?
Mounjaro itself is not likely to be the cause of your hair loss – instead, it’s the weight loss resulting from tirzepatide use that is probably causing your hair to temporarily fall out. When you lose a lot of weight over a relatively short space of time, your body will prioritise more important, life-sustaining bodily functions, including organ function, immunity, and metabolism, rather than hair growth.
So, for a while, your hair growth may slow down or stop altogether. This is a sign that you are losing weight too fast. However, there are several other factors which may also be contributing to your hair falling out, such as:
Nutrient deficiencies
Rapid weight loss can cause nutritional deficiencies. Research shows that following a low-calorie diet can lead to deficiencies in:
- vitamin D
- vitamin C
- selenium
- iron
- zinc
Low levels of vitamin D and C, as well as zinc, biotin, and iron, can all contribute to telogen effluvium or androgenetic alopecia.
That’s why it is important to make sure that your diet on Mounjaro provides all the nutrients you need, even when attempting to lose weight.
Stress
Rapid weight loss is recognised by the body as a form of stress, and stress can induce telogen effluvium or hair loss. One study investigating the link between telogen effluvium and weight loss found that hair loss occurred following an average weight loss of 15.2% or the equivalent of 3.54kg per month.
This is interesting because Mounjaro can help people lose up to 22.5% of their starting body weight at the highest dose after 72 weeks. So, rapid Mounjaro weight loss could cause stress on the body, causing hair loss.
Hormone imbalances
Weight loss can disrupt hormone balance in the body, and these shifts can interrupt the hair growth cycle, increasing the rate at which your hair sheds.
What to do if you’re experiencing Mounjaro hair loss
If you are experiencing hair loss when taking Mounjaro, it’s usually temporary and improves once your body gets used to your new weight.
However, there are things you can do to help prevent and manage hair loss on Mounjaro to boost your confidence and keep you on track to achieve your weight loss goals. They are:
Try to lose weight steadily
A recommended goal for safe, effective, and sustainable weight loss is 0.5 to 1kg per week. Hair loss can be a sign that you are losing weight too quickly, which puts strain on your body. Aiming to lose a small and consistent weekly amount can help limit hair loss.
If you’ve changed your diet and lifestyle all of a sudden when starting Mounjaro, you may see a bigger drop in weight at the start of your journey. If you think you’re losing weight very quickly at a lower dose of Mounjaro, and you’re getting hair loss, speak to your doctor about staying at a lower dose of Mounjaro for longer to see if things level out first.
Follow a healthy, balanced diet
For optimal results, Mounjaro should be paired with a calorie-controlled diet and exercise, but your diet must not restrict the essential nutrients your body needs to function. Make sure you’re eating enough:
- protein
- zinc
- iron
- biotin
This can promote healthy hair growth and prevent excess shedding.
Stay hydrated
Proper hydration is very important for healthy hair growth because water:
✓ supports the function of hair follicles
✓ facilitates the transport of essential nutrients
✓ limits dryness and breakage
It’s recommended that adults aim to drink 6 to 8 glasses of fluid per day, prioritising water over things like coffee, juices, and fizzy drinks.
Manage stress
Stress is a major contributory factor to hair loss, with some research suggesting 73% of people with hair loss experience stress. Managing stress is an important preventative measure for further hair loss because it can make telogen effluvium worse, leading to increased shedding.
You can help limit stress by:
- practising mindfulness, meditation, or breathing exercises
- journaling
- taking part in regular exercise
- getting good and restful sleep
Use gentle hair care products
Hair styling products and techniques can strain your hair follicles and contribute to excess shedding. Where possible, try to avoid:
✗ excessive heat styling
✗ harsh chemicals
✗ tight hairstyles
This will help to promote healthy hair growth.
Be patient
Although Mounjaro hair loss is normally temporary, it can take time for your hair to grow back. Stressing about hair loss can make it worse, so be patient and focus on your health and give your body time to adjust to your new lifestyle.
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Frequently asked questions
Is the hair loss from Mounjaro permanent?
No, hair loss from Mounjaro is not usually permanent. Hair loss caused by rapid weight loss can be worrying, but it is usually reversible, and as your body gets used to your changing weight, your hair should begin to regrow. Most people notice regrowth within 3 to 6 months.
How long does hair shedding last on Mounjaro?
Mounjaro hair shedding is often temporary and reversible, and most people can expect their hair to regrow within 3 to 6 months after shedding begins.
Do other GLP-1 medications like Wegovy also cause hair loss?
Yes, hair loss is listed as a common Wegovy side effect. However, like Mounjaro, it’s unlikely that the medication itself causes hair loss, but rather the rapid rate at which your body composition changes.
When should I talk to a doctor about hair loss while on Mounjaro?
Talk to your doctor if you’re taking Mounjaro and your hair loss has lasted longer than 6 months or you’re getting other symptoms, such as fatigue or brittle nails, because this could be a sign of an underlying condition.
Your doctor can check for nutrient deficiencies, thyroid issues, or other health conditions which may be contributing to weight loss and suggest appropriate treatment or adjusting your Mounjaro dose.
After completing her first degree, she went on to study graduate-entry medicine at Warwick University. After graduating as a doctor, she worked within the West Midlands in Urology, Respiratory Medicine, Infectious Disease, and Psychiatry before transitioning into a full-time medical communications role.
Meet our doctorsLast reviewed: 29 Jul 2025
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Do Ozempic, Wegovy, Mounjaro & Zepbound cause hair loss?, Drugs.com [accessed 10 July 2025]
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Micronutrient deficiency in obese subjects undergoing low calorie diet, Nutrition Journal [accessed 10 July 2025]
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Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen, emc [accessed 10 July 2025]
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Stress-Related Hair Loss Among the General Population in Al Majma'ah, Saudi Arabia: A Cross-Sectional Study, Cureus [accessed 10 July 2025]
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Telogen Effluvium, NIH [accessed 10 July 2025]
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