Mounjaro and Hair Loss: What You Need to Know

While Mounjaro is an effective medication for weight loss, it can cause side effects such as hair loss. Here, we discuss the connection between Mounjaro and hair loss, why it can happen, and what you can do to manage it, so you maintain both your weight loss goals and confidence throughout your journey.

Yes, hair loss is listed as a common Mounjaro side effect, potentially affecting up to 1 in 10 people who use it. One study found that alopecia (hair loss) was reported in 4.9 to 5.7% of people taking tirzepatide for weight loss, with it being more common in people taking the highest dose and losing the most weight.

Interestingly, a more recent study found that treating type 2 diabetes in someone with androgenetic alopecia (pattern hair loss) with tirzepatide improved hair loss, although more research is needed.

It’s unlikely that the medication itself is causing hair loss, but the rate at which your body is losing weight causes your hair to shed rapidly. Losing weight quickly can be recognised by the body as a form of stress, and research shows this disrupts the normal hair follicle cycle, resulting in hair loss.

There are several potential reasons why you might experience hair loss when losing weight. Mounjaro is unlikely to be the direct cause of your hair falling out, but rather the changes occurring in the body. Rapid weight loss can disrupt the normal hair follicle cycle, while stress, hormonal changes, or nutrient deficiencies can also contribute.

Rapid weight loss and telogen effluvium

Rapid weight loss can cause a temporary condition called telogen effluvium. The fast and significant loss of weight is seen by the body as a form of stress, causing a high number of hair follicles to enter their resting phase, which results in increased shedding.

One clinical trial found that hair loss occurred at an average weight loss of 15.2%, with women and older adults more likely to be affected. This is particularly interesting as the average weight loss on Mounjaro is 22.5% at the highest maintenance dose. So, the rapid weight loss that can happen on Mounjaro could contribute to hair loss.

Nutrient deficiencies

Nutrient deficiencies can cause hair loss when you are losing weight, especially if your diet lacks:

• protein
• iron
• zinc
• other essential vitamins and fatty acids

That’s why when you choose Mounjaro, or any other GLP-1 medication, it’s important to follow a healthy, balanced diet that provides all the nutrients your body needs.

Hormonal shifts

Hormonal shifts from rapid weight loss can trigger the resting phase of the hair life cycle, resulting in excess shedding and hair loss.

Some of the hormone changes that can trigger hair loss during weight loss are:

• reduced oestrogen – a female sex hormone
• increased cortisol – a stress hormone
• thyroid hormone imbalances – hormones that regulate important body functions, including energy, heart rate, and metabolism

Mounjaro is indirectly associated with affecting hair growth stages by triggering telogen effluvium, which is a temporary condition where hair follicles are shocked into an early resting phase by factors including rapid weight loss or reduced calorie or protein intake.

There are 4 distinct stages of hair growth. They are:

1. Anagen phase. Also known as the growth phase, this stage lasts for 2 to 8 years. Rapid weight loss can cause active hair follicles to end this phase prematurely.
2. Catagen phase. Begins when the anagen phase ends and lasts for around 2 weeks. During this time, the hair follicles shrink, slowing hair growth. Body changes caused by Mounjaro can fast-track hair follicles past this stage.
3. Telogen phase. This phase lasts 2 to 3 months, during which no hair growth happens. However, following rapid weight loss, more hairs enter this phase, causing noticeable hair loss.
4. Shedding phase. Also known as the exogen phase, it occurs 2 to 4 months after starting Mounjaro or rapid weight loss, and results in resting hairs noticeably falling out, particularly when brushing or washing your hair.

Some research suggests an increased risk of telogen effluvium with tirzepatide use, but hair loss is not just linked to Mounjaro.

Recent research into different GLP-1 medications has found a higher number of reported cases of alopecia in people taking semaglutide and tirzepatide (Wegovy and Mounjaro). However, hair loss was only noted in people taking weekly weight loss injections and not daily injections, like liraglutide (Nevolat).

As hair loss and rapid weight loss are often linked, it’s worth noting that liraglutide typically causes less weight loss over time, with studies showing an average 8% loss after 56 weeks, which may explain why hair loss was not reported in people taking it.

When does hair loss start when using Mounjaro?

Hair loss can occur within 2 to 4 months of starting Mounjaro treatment as your hair enters the telogen phase. However, it is often temporary and is caused by the physical stress of losing weight quickly and sometimes from nutrient deficiencies, rather than Mounjaro itself. Most people notice that their hair regrows within 3 to 6 months after the shedding begins.

If you notice hair thinning while taking Mounjaro, there are several steps you can take to reduce shedding and support regrowth. Strategies include eating a nutrient-rich diet, making sure you get enough protein, considering supplements, managing stress, and seeking professional advice if hair loss persists.

Aim for steady weight loss

Steady weight loss is key when it comes to preventing hair loss. It is recommended that you aim to lose between 0.5 to 1kg per week, for safe and sustainable weight loss. Hair loss is a sign that you may be losing weight too quickly, as it shocks your hair follicles to enter the resting phase prematurely, resulting in shedding.

If you are concerned about how quickly you are losing weight or hair loss while using Mounjaro, speak to your doctor. They may recommend staying on a lower Mounjaro dose for longer to see if this helps.

Nutrition

Diet plays an important role in hair health. Rapid weight loss can sometimes affect how well your body takes in nutrients from your food, which in turn impacts hair growth cycles. To protect your hair, make sure you’re getting enough of the following nutrients:

If you’re struggling to meet your nutritional needs through your diet, you might need to consider taking supplements. You should always speak to your doctor before starting any new supplements while taking Mounjaro or any other medication.

Biotin supplements

There is a lack of conclusive evidence that biotin supplements are effective for hair loss in healthy individuals. It has a crucial role in the production of keratin, the main protein that builds healthy hair, skin, and nails. However, you can get your daily biotin requirements through your diet by eating foods such as:

• eggs
• fish
• meat
• nuts
• seeds

Hydration

Staying hydrated is important for hair health because it improves the delivery of nutrients to follicles and prevents dry, brittle strands that break easily. It is important to:

✓ drink 6 to 8 glasses of fluid per day, preferably this should be water rather than coffee, tea, juices, and fizzy drinks

✓ eat foods that have a high water content such as cucumbers, watermelon, and leafy greens

✓ keep your electrolyte levels balanced, especially if you sweat a lot during exercise or in hot weather, to keep your fluid levels steady

Lifestyle and self-care

As well as your diet, there are certain lifestyle factors that can contribute to hair loss, particularly when you’re losing weight. Some of the things you should aim to do include:

Hair loss treatments

Although Mounjaro hair loss is usually temporary, you may choose to use hair loss treatments, like topical minoxidil, to help reduce the effects and help stimulate your hair follicles to promote growth.

Use or hair loss service for men or hair loss service for women to see if any treatments are suitable for you.

Get medical advice

If hair loss continues or gets worse, you should let your doctor know. They can run further tests to check for nutrient deficiencies, hormone imbalances, or thyroid issues, which may be contributing to hair loss. They can also support or refer you to therapies if stress is the cause.

It’s not necessary to stop taking Mounjaro because of hair loss. Although hair loss can be worrying, it’s been shown in most cases to be temporary and manageable. Often the benefits of continuing weight loss treatment outweigh the risks.

For example, Mounjaro can support you to lose an average 22.5% of your initial body weight on the highest dose, and with weight loss comes added health benefits, including:

✓ reduced risk of diabetes

✓ lower rates of heart disease

✓ healthier joints

If you are concerned about hair loss, you could ask to stay on a lower maintenance dose (5 or 10mg), which may cause less rapid weight loss than the higher doses.

Although hair loss is listed as a common side effect, it’s unlikely to be directly caused by Mounjaro. It’s more likely to be caused by the rapid weight loss that occurs when you take it.

Hair loss on Mounjaro is usually temporary and manageable, with the benefits of taking Mounjaro usually outweighing the risks of hair loss. If you’re concerned about Mounjaro hair loss, our doctors are on hand through your patient account to offer support and guidance.

Does Mounjaro cause hair loss directly?

No, Mounjaro is unlikely to directly cause hair loss. Instead, shedding is more likely the result of rapid weight loss and could also be related to nutritional changes.

Why do some people lose hair while on weight loss injections?

Some people get hair loss when they’re using GLP-1 medications like Mounjaro or Wegovy because of the rapid weight loss they cause, which can be recognised by the body as stress. This causes hair follicles to enter their resting phase, leading to increased shedding. However, not everyone will get hair loss as a side effect.

Is hair loss from Mounjaro permanent?

No, Mounjaro hair loss is not usually permanent and is often reversible as your body gets used to the change in your weight. Most people notice hair regrowth within 3 to 6 months.

Do other weight loss medications cause hair loss?

Yes, hair loss is also a common Wegovy side effect. However, just like Mounjaro, hair loss is unlikely to be caused by Wegovy’s active ingredient, semaglutide, itself, but by the rapid rate at which you lose weight while taking the medication.

Hair loss can also happen in people who do not use weight loss medications if they lose weight too quickly. Losing weight at a steady pace is key to preventing this side effect.

Will my hair grow back after stopping Mounjaro?

Yes, Mounjaro hair loss is usually temporary and will grow back, with most people noticing new hair growth within 3 to 6 months after the shedding began, even while still using Mounjaro. If you are concerned about hair loss while using Mounjaro, speak to your doctor for more advice.

Should I stop Mounjaro if I notice hair thinning?

No, you should not stop taking Mounjaro if you notice hair thinning or loss without speaking with your doctor. Hair loss on Mounjaro is often temporary and caused by rapid weight loss or nutritional deficiencies, and not the medication itself. Your doctor can assess underlying causes and advise on how to treat them or how you can manage hair loss in the short term.