Mounjaro® Hair Loss: Why It Happens & How to Stop It

Hair loss is a reported experience for some Mounjaro® users. While increased shedding and noticing more hair in your hairbrush can be alarming, it’s usually not a direct side effect of the medication itself, but rather a result of rapid weight loss. Hair loss on Mounjaro® is usually temporary and improves as your weight stabilises and your body adjusts.

Here we’ll explain what causes hair loss on Mounjaro®, whether it will grow back and what you can do to reduce the risk of hair loss while taking weight loss medication, so you can focus on reaching your weight loss goals.    

Does Mounjaro® Cause Hair Loss?

Yes. Mounjaro®’s patient information leaflet lists hair loss as a common side effect, affecting up to 1 in 10 people who use it.* Clinical trials have shown that 4.9% to 5.7% of Mounjaro® users reported hair loss.⁺ However, it is not tirzepatide, the active ingredient in Mounjaro®, that is causing hair loss, but the rapid weight loss that has occurred because it places physical stress on your body that can disrupt your hair follicle growth cycle.ⱽ This is called telogen effluvium.

Several factors can cause telogen effluvium while taking Mounjaro. They are:

• Rapid weight loss – Rapid weight loss can induce telogen effluvium, a temporary form of hair loss that occurs when the body is under added stress and sends many hair follicles into their resting phase. This can cause increased shedding, which is why you may have noticed more hair in your hairbrush or in the shower than usual if you have been using Mounjaro and have lost a lot of weight.

• Inadequate nutrition – One of the most common effects of Mounjaro® is that it suppresses your appetite, causing you to eat less. This can create gaps in your nutrition and mean you’re not getting enough essential vitamins and minerals, like protein, zinc and B vitamins, to support healthy hair growth.

• Stress – Major lifestyle changes, such as taking medication, illness, weight loss, or stress, can affect your hormones, including cortisol levels, which can lead to hair thinning or loss. 

Hair loss isn’t exclusive to Mounjaro®, though. It can also happen with other weight loss methods, such as other GLP-1s including Wegovy®, bariatric surgery and even extreme dieting. One study found that the average weight loss associated with telogen effluvium was 15.21%, and it occurred in people who lost weight intentionally and unintentionally, and did not include GLP-1s. In the study, hair loss began after 1.12 months of losing weight and improved, on average, after 4.83 months.ˣ At the highest weekly dose of Wegovy (7.2 mg), hair loss affects 5.3% of people, compared with 1% on placebo, which is similar to Mounjaro®.⁻

*Electronic Medicines Compendium. (2026). Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen.

⁺Jastreboff, A. M. (2022). Tirzepatide Once Weekly for the Treatment of Obesity.

ⱽBurke, O. et al. (2025). Glucagon-like peptide-1 receptor agonist medications and hair loss: A retrospective cohort study.

ˣKang, D. et al. (2024). Telogen Effluvium Associated With Weight Loss: A Single Center Retrospective Study.

⁻Electronic Medicines Compendium. (2026). Wegovy 0.25 mg, FlexTouch solution for injection in pre-filled pen.

Does Mounjaro® cause hair thinning?

Yes. Although Mounjaro® does not directly damage hair follicles, it can cause temporary hair thinning due to rapid weight loss. Losing weight quickly shocks your body. This can cause your hair follicles to enter their resting phase early, as your body focuses on other important functions. Don’t worry, this type of hair loss is usually temporary and improves once your body adjusts to your new weight.  

When Does Hair Loss Start on Mounjaro®?

Mounjaro®-related hair loss tends to be noticeable 2 to 4 months after you start treatment or when you lose weight rapidly.* It’s usually temporary, often only lasting several months, and tends to improve once your weight stabilises. However, not everyone who takes Mounjaro® will experience hair loss, and if you do, when and how it affects you depends on your dose, the rate at which you have lost weight, and your diet and nutritional status. 

* Lang, K. (2026). Does Mounjaro cause hair loss?

Will Hair Grow Back After Mounjaro® Hair Loss?

Yes. In most cases, Mounjaro® hair loss is temporary and starts to regrow within 3 to 6 months, but it can take up to 1 year. Telogen effluvium is not permanent and resolves once the trigger is resolved or your body adjusts to your new weight. One study found that the average recovery period for telogen effluvium caused by weight loss was 5 months for men and 4.78 months for women, but this can vary from person to person.*

* Kang, D. et al. (2024). Telogen Effluvium Associated With Weight Loss: A Single Center Retrospective Study.

How to Prevent or Reduce Hair Loss While on Mounjaro

If you’re feeling anxious or worried about hair loss on Mounjaro®, don’t worry, you’re not alone. Remember, it is usually a temporary side effect of significant weight loss and part of the journey to the ‘new’ you. You can do a few things to help prevent or reduce hair loss while on Mounjaro®, so you can focus on your weight loss plan. Here are our top tips. 

Follow a healthy, balanced diet

Diet plays a major role in hair health, and when you start Mounjaro® for weight loss, one of the first changes may be your appetite. Because you may eat less to reach a calorie deficit, you may also miss some of your daily nutritional targets. Following a healthy, balanced diet that incorporates a wide range of foods, from lean meat and fish to colourful fruit, vegetables and wholegrains is a great way to ensure your body is getting all of the macro- and micronutrients it needs to stay healthy.

Protein is a key nutrient your hair needs to stay healthy, especially since hair is mostly made up of a specialised protein called keratin. It’s also easy to overlook during weight loss without a diet plan. Your body cannot break down and absorb keratin. So, eating protein-rich foods that supply the amino acids (building blocks) your hair follicles need to build keratin is key.* Aim to eat 0.8 to 1g of protein per kilogram of body weight per day⁺ from foods such as:

• Lean meat

• Chicken

• Eggs

• Tofu

• Beans

• Lentils 

* Trüeb R. M. (2021). "Let Food be Thy Medicine": Value of Nutritional Treatment for Hair Loss.  

⁺Wu, G. (2016). Dietary protein intake and human health.

Consider taking supplements and vitamins

If you have struggled with your appetite while taking Mounjaro® and have become deficient in some nutrients, taking supplements may help. However, taking more than you need, or taking them if you are not deficient, will not make your hair grow faster or thicker and may even cause side effects. Most people who eat a healthy, balanced diet will get all the nutrients their body needs without taking supplements.

Some of the most commonly taken supplements and nutrients for hair health are:

• Iron

• Zinc

• Biotin

• Vitamin D

• Vitamin B12

For example, you may have read or heard about biotin supplements for hair growth. Yet, no conclusive evidence shows that taking biotin supplements if you are already healthy or not deficient in it will help hair loss.* 

If you are concerned you may be deficient in certain vitamins or minerals because your appetite has decreased while taking Mounjaro®, or you are finding it difficult to eat certain foods because of side effects, speak to your clinician for advice and read our “Best Vitamins for Hair Loss” guide.

* Patel, D. P. et al. (2017). A Review of the Use of Biotin for Hair Loss.

Lose weight steadily

Have you ever heard the saying “slow and steady wins the race”? Weight loss is no exception. When you lose weight really quickly, it sends your body into a state of shock, and it focuses all of its energy on survival, which means that functions that are thought to be less important, such as your hair growth, take a backseat. That’s why your hair follicles enter their resting phase early: your body doesn't view healthy hair as important as vital functions like breathing, keeping your blood pumping, and moving and using energy. 

So, one of the easiest ways to help prevent hair loss on Mounjaro® is to lose weight at a safe, steady rate. We recommend aiming to lose weight at a rate of 0.5 to 1kg per week for safe, sustainable weight loss,* which may help reduce your risk of hair loss.

If you think you may be losing weight too quickly on Mounjaro®, speak to your Hers clinician, who may advise remaining on a lower dose for longer to help your body adjust.

* NHS. (2026). Overweight and obesity in adults.

Gentle hair care habits

Along with factors like diet, stress, and rapid weight loss, even how you care for or style your hair can contribute to hair loss. Some of the things you can do to help include:

• Avoid excessive heat such as hair straighteners, tongs and hairdryers

• Avoid tight hairstyles such as tight braids, ponytails and cornrows, which can put extra stress on hair follicles and strands

• Use gentle haircare products that do not contain harsh chemicals and stay on top of your haircare routine

Stay hydrated

Hydration is more important for hair health than you may have realised. Staying hydrated supports your circulation and ensures essential nutrients reach your hair follicles. It can also prevent other complaints, such as a dry scalp and dandruff, improving your hair's appearance.

You can increase your hydration levels by:

• Drinking 6 to 8 glasses of water or fluid per day, this includes water, clear fluids and herbal teas

• Eating foods with a high water content, such as watermelon, cucumbers, strawberries, celery and leafy greens

• Monitoring your electrolyte levels, especially during periods of hot weather or if you sweat a lot during exercise

Manage stress levels

Severe or chronic stress can cause hair loss by pushing hair follicles into a resting phase, which ultimately increases shedding.* If stress is causing or contributing to your hair loss, there are several things you can do, such as:

• Aiming to get 7 to 9 hours of sleep per night

• Avoiding too much sugar and caffeine, especially before bed

• Getting regular exercise

• Practising mindfulness, meditation or yoga

• Talking to someone you trust about how you are feeling

• Removing yourself from the stressful situation or limiting your exposure to the trigger

If you are concerned about how stress is impacting your daily life, make an urgent appointment with your GP for advice.

* Choi, S. et al. (2021). Corticosterone inhibits GAS6 to govern hair follicle stem-cell quiescence. 

When to See a Doctor or Dermatologist

If your hair loss is persistent, lasts more than 6 months, or you develop additional symptoms such as fatigue, mood changes, visible bald patches or other scalp-related issues, contact your GP for advice. They may need to do additional checks and tests to rule out other underlying causes such as thyroid problems, hormone imbalances, iron deficiency or anaemia. 

If you are concerned about hair loss on Mounjaro®, your Hers clinician can discuss adjusting your dose or staying on a lower dose longer than the typical dosing schedule to help slow weight loss or give your body more time to adjust. 

FAQs

Will cutting my dose or pausing Mounjaro® stop the hair loss?

No. Cutting your Mounjaro® dose is unlikely to stop your hair loss immediately. Hair loss on Mounjaro is not caused by the medication itself, but by the rapid weight loss it helps to facilitate. When you lose weight quickly, it can shock your body, causing your hair follicles to prematurely enter their resting phase and increase shedding. So, lowering your Mounjaro® dose is likely to have little effect. The good news is that once your body adjusts to your new weight, your hair loss should improve. 

Is Mounjaro® hair loss permanent?

No. Hair loss from Mounjaro is not permanent and usually reverses when your body adjusts to your new weight and lifestyle.

Is Mounjaro® hair loss worse for women?

No. Hair loss is not worse for women, but women are more susceptible to telogen effluvium.* It is the most common cause of hair loss in women, followed by female pattern hair loss and chronic telogen effluvium.⁺ Mounjaro® hair loss is likely to be more frequently reported and may be more noticeable in some cases in women than in men, especially as it can be linked to a reduction in oestrogen and other hormones. 

*Kang, D. et al. (2024). Telogen Effluvium Associated With Weight Loss: A Single Center Retrospective Study.

⁺Agarwal, S. et al. (2019). Diffuse Hair Loss in Females.

Does hair loss get worse around my period or during perimenopause?

Yes. You may notice increased hair shedding during perimenopause because oestrogen and progesterone drop. These hormones usually help to keep your hair thick, healthy, and in its active phase, so when they decline, your follicles may enter their resting phase, leading to increased shedding. If you're worried about hair loss, discuss treatment options with your GP.

Should I stop Mounjaro® if I notice my hair thinning?

No. If you notice your hair thinning or have noticeable hair loss while taking Mounjaro®, speak to your clinician before stopping treatment. Mounjaro® hair loss is usually temporary and caused by rapid weight loss, not the medication itself, so stopping it may not help much. Your clinician can discuss the potential cause and how to manage it if hair loss is affecting you.