Do GLP-1s Cause Hair Loss? Experts Explain The Rising Side Effect.

Just when you thought you knew what to expect with GLP-1s, new research emerges that gives you pause. A study published earlier this year in the Journal of the American Academy of Dermatology International discovered a link between GLP-1 usage and hair shedding. The study looked at more than 550,000 patients and found increased odds of hair loss associated with using GLP-1s like Ozempic, Wegovy, Zepbound, and Mounjaro. So, not only do you run the risk of your face looking more gaunt and sunken after using a GLP-1 medication, you’re also facing your hair potentially peacing out.

While this side effect may not be a dea-lbreaker for those taking the drug to aid their weight-loss journey, it’s not ideal. Suddenly seeing an uptick in hair fall can be alarming, to say the least. Ahead, TZR talked to the experts to answer some of your biggest questions around GLP-1s and hair loss, so you can better understand what to expect and, most importantly, what you can do about it.

Do GLP-1s Cause Hair Loss?

The irritating answer here is yes and no. While we might colloquially refer to it as hair loss, what’s actually happening is a massive shedding event. This temporary loss of strands differs from true hair loss (more on that later). As for whether the GLP-1s themselves are responsible for hair falling out, according to Dr. Joyce Park, M.D., FAAD, a board-certified dermatologist in Seattle and founder of Kerativ, doctors can’t definitively say that GLP-1s don’t cause hair to shed. The prevalent wisdom is that it’s not the medication itself, but rather the weight loss. “What we’re seeing now with GLP-1s runs in parallel to what I’ve seen in practice with bariatric surgery patients and crash-dieting patients,” she says. “When patients undergo a significant stressor in their lives, that resets and shocks a lot of their hairs from the antigen growing phase into the telogen resting phase. About three to four months after the stressor, you get this massive exodus and shedding of hair.”

What makes it more difficult for providers is that they are only now starting to see the impacts of GLP-1 usage as it becomes more accessible. “GLP-1s, even though they have boomed in popularity, we're still in the early phases of truly understanding what's an effect of the GLP-1 as a medication and what’s actually a result of the weight loss,” says Dr. Marisa Garshick, M.D., FAAD, a board-certified dermatologist in New York City. Adds Jay Small, a trichologist and co-founder of Arey, it also took some time for experts to differentiate between shedding that was GLP-1 related and what was potentially hormone related. “I've been tracking hair loss in all of my personal clients that are on GLP-1s since last spring,” he says. “A lot of the early adopters of GLP-1s were postpartum women or someone perimenopausal that was struggling with weight loss.” According to a recent survey, nearly 12% of Americans are or have used a GLP-1, nearly three times as many as in 2020. Women aged 30-49 (i.e., those most likely to be in perimenopause) are twice as likely to have been on a GLP-1 than their male peers.

But losing weight is only part of the story, says Park. There are two other potential triggers for hair shedding that come with GLP-1s. The first, she says, are nutritional deficiencies and dietary changes. “You have decreased overall calories, decreased protein intake, and then decreased nutrients that you really need for growing hair,” she says. Many people on GLP-1s, says Small, are not only eating fewer calories, but they are incorporating less healthy food in their diet. “People are eating less and thinking ‘I can have fun food — it’s not going to do as much to me.’ They’re not eating nutrient-dense food,” he says. “They're having a protein shake, or a protein bar. It's providing potential sustenance in a way, but it's not giving you iron, copper, B vitamins — things you need for healthy hair.”

The second potential trigger, says Park, is one that also impacts those who aren’t on a GLP-1. According to a recently released study in Cell, intermittent fasting can be an underlying cause for hair loss. “The idea is that intermittent fasting can also release stress signals to the fat cells in your dermis, and that can trigger apoptosis, or cell death, in your follicular stem cells,” explains Park. “Researchers were finding that unstable nutrient supply through intermittent fasting, which we can see mimicked in GLP-1 users, can cause a release of reactive oxidative species within your hair stem cell environment, which can actually cause cell death for your hair follicle stem cells.” Follicular cell death is probably not something any of us had on our bingo cards for potential GLP-1 side effects.

So What Exactly Is Happening To Your Hair?

Another reason we are just starting to understand the effects of GLP-1 use on the hair is because it’s a very specific kind of hair loss that’s not actually hair loss, called telogen effluvium. “It’s a shedding event where the body automatically turns off the growth cycle for a majority of hair and those hair strands then fall out,” explains Small. And that distinction is important, says Garshick. “Shedding is your hair falling out — you're noticing more on the table, in the shower — whereas thinning is you’re noticing fewer hairs on the scalp,” she says.

While you might not care about the difference between the two when your hair is coming out in giant clumps, it is important because it will change how you treat it. According to Garshick, GLP-1 related telogen effluvium is typically caused by stress as your body attempts to conserve energy and focus on supporting your vital organs, of which hair is not one. “Hair lives in three different phases: a growing phase, a resting phase, or a falling-out phase,” says Garshick. When your body is experiencing significant stress, your hair becomes stuck in that resting phase, she notes.

Typically, says Park, 90% of your hair is in the antigen growing phase and 10% is shedding. “Growing hair is a metabolically demanding function, so when you're in that stressed state, your body is going to shift those antigen hairs into telogen resting hairs. Instead of 10% of your hair being in telogen, it might shift to 20% to even 50%.” So instead of a few hairs in your brush or on your shirt, up to half of your existing hair strands are falling out at once. What’s even more confusing is that it takes about three months after exposure to the stress — i.e., the GLP-1 weight loss — to see this happen. Because of that delay, many users don’t draw the connection between the two.

Is It Permanent?

Some good news: Telogen effluvium is typically not considered permanent. “I usually say it may take two to three months for somebody to notice the shedding, then maybe it plateaus and exists for another two to three months,” says Garshick. “But then after another three to six months, hair will start growing back. For a lot of people, the whole cycle does get better on its own, but it can sometimes be almost a year before you really see the positive normalization of how the hair's growing.”

This is different from the type of true hair loss you may be familiar with called androgenetic alopecia, what is commonly referred to as male or female pattern hair loss. The difference between the two, says Park, is that in telogen effluvium, the hair sheds very suddenly and all over the scalp. “Whereas androgenetic alopecia, there are specific areas where we see concentrated hair loss,” she explains. For women, that is usually a widening of their hair part, whereas for men it’s typically the crown of the head and around the temples. It tends to happen more gradually over time, to the point where you may not notice the changes right away or that they are even significant, explains Garshick. And, unless you intervene with treatments like red-light therapy, platelet-rich plasma (PRP) therapy, or prescription minoxidil, that hair won’t return on its own. She does point out that there is sometimes an overlap of people who have androgenetic alopecia and then go on a GLP-1 and experience telogen effluvium. In those cases, while the hair lost will grow back, you may see it’s thinner or your baseline may not recover to its pre-weight-loss look. “They may actually find that their new set point is a little thinner, a little more sparse in terms of the number of hair follicles than it was because it's not as resilient,” says Garshick.

Who Is Most At Risk?

If you are taking a GLP-1, odds are high that you will experience this type of hair loss, regardless of age, weight, or sex. However, Park says the type of GLP-1 and how much of it you take may have an effect. She points to a recently released review that demonstrated that hair loss associated with a semaglutide — like Ozempic or Wegovy — was dose dependent. “The lower doses, which were defined as less than 2 milligrams a week, were not as implicated in hair loss cases, whereas anything above that was more commonly associated with hair loss,” she says. Interestingly enough, the review also found that the tirzepatides — Mounjaro and Zepbound — were linked to higher rates of telogen effluvium and, consequently, more hair loss. “The hypothesis is because tirzapeptides are linked to more weight loss,” she explains. “That goes along with the dosing correlation that the higher the dose, the more weight loss you have and then the more telogen effluvium you have.”

Can You Prevent Hair Shedding?

While you can’t totally prevent telogen effluvium, you can help make it less of a shock to your system. Garshick says your first step before going on a GLP-1, especially if hair loss is already a concern, is to talk to your doctor. That will help you understand what type of weight loss you can expect, so your doctor can help you craft a well-balanced diet that is rich in protein. “For hair, we know protein is essential,” she says. “So whether or not you're experiencing the shed, having the healthiest hair possible is important.”

She also says to avoid adding any unnecessary stress to the scalp. That means no chemical treatments or processing — now is not the time to decide you want to go platinum blond. “You want to optimize the conditions of the scalp,” she says, “so try to hold off on those if you’re trying to be as precautious as possible.” In that same vein, Park says that if you have any suspicions that you may have androgenetic alopecia, talk to your dermatologist. “If you’re going to go on a GLP-1, start treatment preventatively,” she says, “because it's going to get worse on the GLP-1. Make sure you don't lose all the weight all at once — slow and steady is better for preserving your hair.”

However, as Garshick wisely notes, taking precautions doesn’t mean your body is going to decide not to shed hair at all. “It's just how we manage that loss and how we deal with it,” she says.

How Do You Treat It Once IT Happens?

For those already on a GLP-1 and worried about experiencing the inevitable shed, the first thing to do is remember that this is a normal side effect (to a degree) and it doesn’t mean you should abandon ship on your GLP-1. “Patients are like, ‘Oh, I'm just going to go off of it,’” says Garshick. “But you're past the hard part. You already experienced the loss. There's no reason that you have to come off now.”

If you’re (rightfully) freaking out about chunks of hair falling out of your head, Park says that, again, your first step should be to talk to your doctor to ensure it’s normal telogen effluvium and not something more nefarious. “If a patient is already on a GLP-1 and experiencing thinning, the first thing I would do is check bloodwork to make sure that they’re not having some underlying disorder that could explain the hair loss,” she says. That means checking red blood cell count to rule out anemia, then testing iron, ferritin, vitamin D, zinc, and thyroid levels. “The second thing is take a look at the distribution of hair loss, the pattern, the duration,” she says. “Is it diffuse hair loss or is it really concentrated in areas that match more with female- or male-pattern hair loss? And then I would also ask about their history of how quickly they lost the weight, what dosage they are taking, and what's their diet like?”

After verifying the above formation, Park says she would suggest patients explore a hair-loss medication. “I usually start patients on topical minoxidil, a 5% liquid or foam, which is good for men and women,” she says. “If the hair loss is severe, I would then think about an oral medication like oral minoxidil or oral finasteride. Oral spironolactone is also a very potent medication for treating female pattern thinning.” Along with a prescription, she would also see what type of at-home care patients are using to best support their hair and scalp. That means rotating in an anti-inflammatory shampoo like Head & Shoulders or Nizarol to reduce excess yeast and remove any chance that inflammation is playing a role in the hair loss. Park also suggests cycling in a microbiome-rebalancing shampoo, like her just-launched Kerativ Redensify Reset Shampoo. “It has caffeine, pumpkin seed oil, zinc, and adenosine to assist all of those different pathways that help nourish your hair, plus velvet seed extract to thicken the appearance of the hair,” she explains.

Both Park and Garshick both suggest adding a scalp serum, with Garshick explaining that healthy hair starts at the scalp. “We think of the scalp as being the soil by which the hair grows,” she says. “So nurturing it with ingredients like niacinamide, glycerin, peptides, and zinc can be very helpful.” She points to the Dove Derma Scalp Density Boost 3-in-1 Scalp Serum as a solid option for those who are discouraged by their visibly thinner hair. “It's actually creating this fullness and thickness for healthier hair,” she says. “What I've found for my patients is that having the hair at least appear fuller and stronger while they're waiting for that three to six months for their natural hair to get back to where it was can be really helpful to support them through that process.”

While nothing takes the place of a well-balanced diet full of the nutrients your body needs, Garshick says that if you are struggling on a GLP-1 to get the nutrition your body requires to grow hair, a targeted supplement could be a good addition to your telogen effluvium support kit. “Focus on what benefits you can get either through supplements or through diet,” she says. “Supplements may be targeted specifically if you're deficient in something, or there are supplements that have a different combination of ingredients that may just help support and strengthen the hair overall.” Arey’s Not Today, Grey is a specialized hair health supplement that contains vitamin D, vitamin B6, folate, biotin, calcium, and selenium to nourish the follicles and support fuller, thicker hair. “When we see a decrease in the nutrient supply, we also see a decrease in ATP, which is scheduled cell turnover,” says Small. “So looking for the standard complex of B vitamins, vitamin D, and iron is going to be the most beneficial.” OMI’s Nourish Hair Growth Peptides is another option. Designed for GLP-1 users, it contains peptides and nutrients that support healthy, strong hair follicles.

If you turn to at-home treatments, don’t expect thick, glossy hair to start sprouting out of your head like a retro Dolly Surprise. Remember that there is no over-the-counter product that is going to physically grow new hair. “The things I would look out for to know if what you are doing at home is working are if your scalp feels calmer and less irritated,” says Park. “For the hair, do you feel like your shedding is slowing or you are seeing less breakage?”

The bottom line? Consistency is key (as well as patience). “People want to see overnight results with hair products, but that just simply is not going to happen,” adds Park. “Consistency is everything, so you have to commit to your routine for at least three months before expecting to see things such as any new growth or thickening hairs.”