Why the Keto Diet Is Making Your Hair Fall Out (and How to Stop It)

Before you started the ketogenic diet, you may have been aware of some of the side effects, like fatigue, constipation, and nausea. Others — like potential hair loss — may come as more of a surprise.

For some people, loss of hair is a very real ramification of the ketogenic (or keto) diet. “The ketogenic diet, which is an extremely low-carb but high-fat diet, is a really restrictive diet,” says Rachel Lustgarten, RD, of the Comprehensive Weight Control Center at Weill Cornell Medicine in New York City. Keto is not just a different version of a standard low-carb diet, such as the South Beach diet or Atkins, though. You must also stick to moderate protein intake (higher protein consumption can kick you out of the state of ketosis, which is when the body burns fat for energy), and it also cuts out many healthy foods, too, like grains, beans, most fruit, and many vegetables, she says.

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The restrictive nature is what can lead to hair loss (and what makes it an unhealthy and potentially dangerous pick for some individuals). “If you’re not following keto in a careful way, something that’s difficult even for dietitians themselves to [guide you on], it’s quite possible that you miss out on important nutrients,” says Lustgarten. These are nutrients that fuel hair growth.

Here are four potential reasons keto is causing hair loss.

1. You May Be Eating Too Few Calories on Keto

For a diet that allows butter and cheese, you’d think you’d be packing in the calories. “Because of the high fat intake, people generally are not as hungry and end up cutting calories,” says Alicia Galvin, RD, who’s based in Dallas. (This is one reason why experts say keto leads to weight loss.) Going too low essentially sends a shock to your body that can lead to a shutdown in less critical functions, like hair growth, she says.

2. You May Not Be Getting the Protein Your Body Really Needs

As mentioned, to keep your body in ketosis, at least on the standard keto diet, you must limit your protein intake. While in a typical American diet, we get enough protein, “it’s possible that being so focused on fat in the keto diet, you’re not getting adequate protein,” says Lustgarten. There are 100,000 hair follicles on your head, of which 90 percent are in the growth phase, thus requiring adequate protein, vitamins, and minerals to maintain a healthy head of hair, notes a study published in December 2018 in the journal Dermatology and Therapy. Without enough of these nutrients, including protein, your mane may suffer.

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3. You May Be Losing Weight Rapidly Due to Ketosis

Many people on the keto diet report quick, temporary weight loss, which is one reason why it remains popular. Yet the stress of both losing weight quickly and slashing protein intake can contribute to what’s called telogen effluvium (TE), points out a study published in January 2017 in Dermatology Practical & Conceptual. TE is when the hair shifts from the growing to resting phase, ultimately leading to temporary hair loss that can appear extremely worrisome, notes DermNet NZ. This can also happen during periods of extreme stress, as well as good surprises and stressors, like having a baby. The catch is that there’s a delay of several months between the stressor and shedding, meaning it can be tough to pinpoint exactly what caused the hair loss.

4. You’re Missing Out on Key Nutrients That Contribute to Healthy Hair

Supplements that promote hair growth and a thick, shiny appearance are popular right now, and they almost universally have something in common: the B vitamin biotin, which promotes healthy hair. Despite the fact that biotin is plentiful in many animal-based foods like eggs and salmon, as the International Food Information Council Foundation notes, Lustgarten says there is a small amount of evidence that following a strict keto diet may lead to biotin deficiency, per a study on mice published in the journal Nutrition. One caution, she points out, is that the research is limited and only in animals (meaning, it’s far from conclusive and human studies are needed). “The data isn’t strong enough to say that everyone on keto needs to take more biotin,” she says. Still, you may want to focus on eating biotin-rich foods at this time.

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How Can You Prevent Hair Loss on the Keto Diet?

To help prevent hair loss, take a multivitamin to cover any potential deficiencies, says Galvin. “A multi will act like an insurance policy and at least provide some base nutrients,” she says. Also, get the protein you need from high-quality sources, such as eggs and poultry, and biotin from foods like almonds, onions, tomatoes, walnuts, salmon, pumpkin seeds, and cashews, she says. If you are already losing your hair and you’re struggling despite having a well-planned diet, “you may need to consider liberalizing your diet a bit or work with someone who can help personalize your eating plan based on your goals,” she says. If you are looking to lose weight and are experiencing side effects from keto, there are other diets you can follow to both lose weight and feel better doing it.