Does Mounjaro cause hair loss?

In this article:

• Is hair loss a side effect of Mounjaro?
• Indirect reasons for Mounjaro hair loss
• How to manage Mounjaro hair loss

In this article

• Is hair loss a side effect of Mounjaro?
• Indirect reasons for Mounjaro hair loss
• How to manage Mounjaro hair loss

Mounjaro (tirzepatide) is a brand-name prescription medication that’s approved by the Food and Drug Administration (FDA) to control blood sugar levels in people ages 10 and older with Type 2 diabetes. Some people who take Mounjaro notice an increase in hair shedding within the first few months of starting the medication. But does Mounjaro cause hair loss, or is it caused by something else?  

Is hair loss a side effect of Mounjaro?

Yes, hair loss is a known side effect of Mounjaro. 

“It’s not as common as many other side effects of Mounjaro, but it’s something that physicians in the hair loss industry often see,” says Gregory S. Keller, MD, a plastic surgeon based in Santa Barbara, California. “In general, the initial shedding tends to start one to three months after weight loss begins. Hairs continue to shed over the next three to six months, and then gradually stabilize.” This type of hair loss is called telogen effluvium.

Typically, hairs grow for several years (anagen phase) before growth stops and the hair follicle loses its blood supply over the course of several weeks (catagen phase). Then, the hairs rest on the head for about three months (telogen phase) before detaching from the scalp. Telogen effluvium occurs when a large number of hairs prematurely enter the catagen and telogen phases, resulting in a noticeable increase in hair shedding. This is often alarming. Telogen effluvium results in more than 200 shed hairs per day. 

A 2022 study found that 4.9% to 5.7% of participants reported alopecia (hair loss) while taking Mounjaro compared to just 0.9% of participants taking the placebo. Hair loss was most common among people taking the highest dose of Mounjaro (15 mg once weekly).

Fortunately, Mounjaro hair loss isn’t permanent because the follicle isn’t damaged during the shedding process. Dr. Keller says hair will regrow over a period of about six months after a person’s weight stabilizes and other contributing factors are addressed. 

Indirect reasons for Mounjaro hair loss

Experts believe Mounjaro doesn’t cause hair loss directly. Instead, hair loss may be a secondary side effect resulting from Mounjaro-induced weight loss, physiologic stress, or nutritional deficiencies.

Weight loss-induced hair loss

Weight loss is a common, and often sought-after,  side effect of Mounjaro. The active ingredient in Mounjaro, tirzepatide, is FDA approved for weight loss and weight management under the brand name Zepbound. Quickly losing weight may be one reason why people experience hair loss while taking Mounjaro. 

“The hair loss I see is most often related to rapid weight loss and metabolic stress,” says Ross Kopelman, MD, a hair transplant surgeon and hair loss expert based in New York City and Palm Beach, Florida. “When patients lose weight quickly, the body prioritizes essential functions, and more hairs shift into the resting phase, leading to telogen effluvium.”

Dr. Kopelman explains that the biggest risk factors for Mounjaro hair loss include the speed and amount of weight loss. 

Nutritional deficiencies

One of the ways Mounjaro promotes weight loss is through appetite suppression. But when you don’t feel like eating, you may not consume enough nutrients. Hair growth requires plenty of protein and a variety of vitamins and minerals, and when these nutrients are in limited supply, the body stops feeding the hair follicles in order to feed more essential tissues (consider that the heart and kidneys need nutrients to function). This can trigger hair loss.

“Loss of appetite can cause nutritional deficiencies such as protein, iron, zinc, vitamin D, vitamin B12, and biotin,” Dr. Keller says. All of these nutrients and more support healthy hair. Iron deficiency in particular has long been associated with hair loss.

Stress

In a 2021 study, researchers from the Harvard Stem Cell Institute found that hair regrowth slows considerably when our bodies are under stress. But stress doesn’t always mean you’re feeling anxious. At the cellular level, stress can manifest as increased inflammation. 

“Metabolites of fat breakdown can cause inflammatory stress,” Dr. Keller says. In other words, the body experiences inflammation when it turns stored fat into fuel. To help lower inflammation, the adrenal glands release a stress hormone called cortisol. That’s the same hormone Harvard researchers linked to a longer resting phase in hair follicles and slower hair regrowth. 

So, even if you live a peaceful and anxiety-free life, the process of losing fat may cause enough stress at a molecular level to trigger hair loss. Other stressors, like illness or surgery, can also further increase hair loss. 

Underlying medical conditions 

Some medical conditions can also trigger or worsen hair loss. “I see a higher risk of hair loss in patients with thyroid issues or underlying androgenetic hair loss [male pattern balding], since medication-related shedding can make pre-existing thinning much more noticeable,” Dr. Kopelman says. 

Lupus, syphilis, hormone imbalances, high fever, major surgery, and severe trauma have also been known to cause telogen effluvium. Chronic conditions that damage small blood vessels, including diabetes, can also cause hair loss due to poor blood supply to the follicles. Alopecia areata, an autoimmune disorder, causes hair loss that’s patchy in nature.

Other medications

Mounjaro isn’t the only medication associated with telogen effluvium. Antidepressants, antifungals, anti-inflammatories, beta blockers, and birth control pills are just a few examples of drugs known to cause hair loss. Review your current medications with a healthcare provider to find out which ones, if any, may be contributing to your hair loss.

How to manage Mounjaro hair loss

Mounjaro hair loss can sometimes be prevented or minimized, but it usually requires some pre-planning. Hair loss is noticeable one to three months after a triggering event, which means it may be too late to do much once your hair has already started to fall out. Be patient. It should start to grow back in about six months, but your healthcare provider may recommend products or medications to rapidly stimulate new hair growth.

“Being in excellent health ahead of taking the drug, losing weight more gradually, keeping stress low, and maintaining nutritional status are great ways to prevent or manage this side effect,” Dr. Keller says. When hair loss has already occurred, he typically uses a defensin-based serum to “naturally stimulate hairs to return to a growth state.”

Dr. Kopelman takes a similar approach. “I first determine whether the hair loss is temporary shedding or underlying genetic thinning. Treatment focuses on optimizing protein intake, correcting nutritional deficiencies, and supporting the hair cycle with medical therapies such as topical or oral minoxidil when appropriate.” 

Talk to a healthcare provider about your risk of Mounjaro-induced hair loss and to discuss hair loss treatment options. Don’t stop taking Mounjaro before talking to your healthcare provider. 

Bottom line

Hair loss is a confirmed side effect of Mounjaro and happens in about 5% of patients. There are several underlying reasons why some people lose hair while taking this medication, so it’s important to talk to your healthcare provider to find out what’s going on. You may have a nutritional deficiency that needs to be corrected or an underlying health condition that increases your risk of hair loss. Fortunately, Mounjaro hair loss is usually temporary.