Mounjaro and Hair Loss: What You Need to Know

Mounjaro is a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist that contains the active ingredient tirzepatide. It’s approved for weight loss and type 2 diabetes in the UK and works by mimicking the effects of naturally occurring hormones to reduce your appetite, minimise cravings, and slow down digestion.

As effective as Mounjaro is for weight loss, some people report hair loss as a side effect, which can be a concern. 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

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.

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.

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.

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:

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.

Alternative weight loss medications

If Mounjaro is not right for you or you are finding the side effects too severe, there are several other options available, such as:

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 Wegovy and Mounjaro cause the same side effects?

Both Wegovy and Mounjaro can cause similar side effects, but how often they occur can be different. You also may get side effects from one and not the other, as each person reacts to a medication slightly differently.

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.