Keto Hair: Can a Keto Diet Cause Hair Loss or Hair Growth?

Have you noticed any hair changes while you were on a keto diet?

You may have heard stories about people who started a ketogenic diet only to experience unexpected hair shedding. However, some believe this can only happen when undergoing extreme calorie restriction or using weight loss medications. Others say that foregoing carbs can actually make your hair grow healthier. So what does science reveal? Can a keto diet cause hair loss or stimulate hair growth? Let’s find out!

Executive summary

This article will tell you everything to know about the relationship between the keto diet, hair loss and hair growth. We will help you discover what people mean when they talk about keto hair, as well as the main ways this diet might affect your hair’s fullness and qualities. You will learn about the main nutrients and caloric intake your hair needs to grow healthy, and how to prepare a well-balanced keto plate to honour those needs. And we will also share the best information about how to support regrowth after keto hair loss and how to read the signs that you may actually be experiencing a different, diet-unrelated type of alopecia.

Key takeaways

The ketogenic diet involves significantly reducing carbohydrate intake and increasing the consumption of healthy fats. When it is started abruptly, especially if accompanied by severe calorie restriction and/or poor food diversity, it can lead to a type of temporary, diffuse hair shedding called telogen effluvium.
Keto hair loss can be caused by the sheer shock of a sudden change in diet, by having insufficient energy for your hair growth process or by nutritional deficiencies that impair hair follicle function. Not getting enough nutrients can cause shedding-prone keto hair, which is dull, dry and brittle, and breaks off more easily than usual.
Keto diet-induced telogen effluvium is normally temporary. It typically starts 2-5 months after the beginning of the diet and ends 3-6 months after the factor that triggered it has been resolved. However, in rare cases, it can become chronic and last for years.
There is evidence that the keto diet may also hold certain hair growth benefits for some people, by reducing the need for insulin production. Lower insulin levels can indirectly improve androgenetic alopecia by decreasing androgen production. Keto may also help manage diabetes better, reducing hair shedding in patients, among other health benefits.
Eating well-balanced meals that contain sufficient calories and the necessary amount of hair growth vitamins and minerals can help prevent keto hair loss. As can taking supplements to treat a known nutritional deficiency. Moreover, good hair styling practices can help avoid additional, unnecessary hair breakage.
While keto hair loss normally resolves on its own, you can help stimulate regrowth using hair loss medications such as Minoxidil or therapies such as platelet-rich plasma hair treatments or red light therapy for hair growth.
If your hair shedding is truly keto-induced, you should normally experience no other symptoms than diffuse hair thinning and, in some people, minor scalp burning. Should you experience patchy or patterned hair loss or show signs of infection or inflammation on your scalp, it is best to see a hair doctor for a proper diagnosis.

What is keto hair loss?

If you follow beauty, hair care or nutrition media, you may have come across the term keto hair loss. This may sound a bit confusing, as it isn’t immediately clear what the keto diet has to do with hair health. However, the food we eat is the main source of energy and nutrients that our hair needs to grow. It is well known that certain mineral and vitamin deficiencies can cause hair loss, as can rapid weight loss and insufficient calorie intake [1][2][3]. So the term keto hair suggests that this specific diet is believed to negatively impact your hair health in a specific way, which we are going to explore.

What is the keto diet?

The Ketogenic diet (or keto diet for short) involves excluding or severely limiting the consumption of carbohydrates (e.g. bread, potatoes, pasta, rice, some dairy, sugar, fruit, etc.) and replacing them with fatty foods (e.g. meat, butter, eggs, nuts and seeds, fatty fish, olive oil, etc.). All carbohydrates contain glucose, the primary substance the body uses to produce the energy it needs to function. The idea is to significantly reduce your glucose intake and to obtain approximately 90% of your calories from healthy fats instead [4].

The guiding theory behind the keto diet is that weight loss occurs when your body starts converting fat into energy instead of using the glucose in carbs. This process is known as ketosis. However, other theories regarding this diet’s mechanisms suggest it may work by suppressing appetite or by forcing the body to produce the glucose your brain needs (a calorie-consuming process) [5].

The keto diet can be quite effective for most people in the short term. However, scientists are divided regarding its long-term weight loss maintenance and health impact [6]. Some believe it to be a safe and effective practice, claiming health benefits in treating obesity, managing diabetes, lowering the risk of cardiovascular disease, and even providing some help in fighting cancer [7]. However, others point out that the keto diet is too restrictive to support high adherence in the long term, that it can increase your LDL (“bad”) cholesterol and that it can cause an unhealthy relationship with food and nutritional imbalances [6].

What do people mean by keto hair?

The term “keto hair” is sometimes used informally to describe hair thinning and loss of strength and shine that may occur while undergoing a keto diet. However, it can often be difficult to trace the hair loss back to the diet, as it can start as late as 2-5 months after starting it [8]. Moreover, the symptoms of keto hair loss are not unique to people who are following this diet; they can be caused by a variety of factors (to be discussed).

What does keto hair look like?

Here are some of the main symptoms you might notice if you are experiencing keto-related hair problems:

Diffuse hair thinning all over your scalp
Sometimes, dry, brittle hair that breaks off easily
Sometimes, dull, lacklustre hair that feels like straw
In some cases, a burning sensation on the scalp, known as trichodynia.

Please keep in mind that keto hair loss should normally not manifest with additional scalp symptoms. See a dermatologist or a trichologist if you notice any of the following scalp symptoms:

Patchy hair loss
Patterned hair loss
Lesions on the scalp
Redness and inflammation on the scalp
Crusts or scales on the scalp

Some people may also notice non-hair-related signs that the keto diet may be too abrupt or restrictive and negatively affecting their body, such as:

Brittle nails
Dry skin
Fatigue and low mood

Prurigo pigmentosa (“keto rash”)
Increased acne and skin oiliness

If you notice these symptoms alongside hair shedding while you are undergoing a keto diet, best to see your GP or nutritionist and get some bloodwork done to make sure you are not experiencing any nutrient deficiency.

How can the keto diet cause hair loss?

The reason why some people’s hair starts to shed visibly a few months after starting their ketogenic diet is that they develop a temporary type of alopecia called telogen effluvium. Here is how that happens and the main mechanisms that can lead to it:

The normal stages of hair growth and telogen effluvium

The human hair growth cycle has 4 distinct phases that succeed each other:

The anagen (growth) phase
The catagen (transition) phase
The telogen (resting) phase
The exogen (shedding phase)

However, not all of your hair follicles are in the same stage at the same time. In a person with healthy hair, the vast majority (80-90%) of the follicles are in the growth phase, around 5% are in the transition phase, and 10-15% are in the resting phase [9].

However, when your hair growth cycle is disrupted, these proportions can change, and an excessive number of follicles can be pushed out of the growth phase into resting. What follows is a period of excessive hair shedding, called telogen effluvium.

Telogen effluvium has numerous triggers, such as physical or psychological stress, medication side effects, insufficient resources for healthy hair growth (nutritional deficiencies), etc. Its only visible symptom is diffuse hair thinning that can cause you to shed between 25% and 50% of your hair (but while your hair may get so thin you can see your scalp, you should not develop bald spots) [1]. Some people with this condition also report a mild burning sensation on their scalp.

The good news is that this condition is temporary, and hair growth will resume without intervention within 3-6 months once the triggering factor has been resolved [1]. However, in rare situations, the hair thinning may persist for up to 10 years, a condition known as chronic telogen effluvium [3]. The reasons for this are not well understood, but the phenomenon seems more common in patients who are under consistent physical or psychological stress over a prolonged period or where several triggers keep overlapping.

The relationship between weight loss and hair loss

Healthy, gradual weight loss is normally beneficial for your body. However, research shows that when undergoing restrictive crash diets, the sudden, rapid weight loss can cause hair loss, as it places significant stress on the body, triggering telogen effluvium. One study [8] found that abruptly losing 15% of your body mass or losing over 3.5 kg/month, you are at risk of developing this condition.

When crash dieting, your body experiences the shock of suddenly transitioning from a plentiful diet to a very restrictive one. Moreover, insufficient calorie intake (fewer than 1000 calories/day) can stifle healthy hair growth by depriving the follicles of the energy they need to produce new fibres [10]. Thus, an excessive proportion of them may be pushed out of the growth phase and into the resting phase, leading to the tell-tale hair thinning.

However, even if you are getting all the calories you need from your diet, you can still develop hair loss if you are not getting all the nutrients and vitamins you need for hair growth. This can easily happen with diets that restrict entire food groups, such as the ketogenic diet. Failing to find a different source to replace the nutrients you would normally have received from the excluded foods can lead to nutrient deficiencies that cause telogen effluvium.

Keto particularities that can impact hair loss

Your hair needs a variety of vitamins, minerals, and protein to grow healthy. Some of the most important micronutrients for hair health are [11][12][13][14]:

Vitamin A
Vitamin B, especially Biotin for hair (B7), Niacin (B3) and folic acid (B9)
Vitamin C
Vitamin D
Vitamin E
Iron
Zinc
Selenium
Magnesium
Copper

While some of these are more easily found in keto-friendly foods (e.g. vitamin A or iron), others are more scarce (e.g. Vitamin C or zinc). So, unless you are being careful about your nutrient intake or supplementing with certain micronutrients, you may end up with deficiencies you don’t even know you have. And they can not only trigger telogen effluvium and make your hair become dry, dull and brittle, they can also cause other cosmetic and health issues.

When an already food-group-restrictive diet includes insufficient calorie intake, the risk of hair loss increases significantly. So if you are only eating specific kinds of food and very small portions, you may be depriving your hair of the precious nutrients it needs to grow strong and healthy and inviting telogen effluvium.

The simple solution to this can be to plan out your keto diet with nutritional balance in mind (to be discussed).

Does the keto diet have any hair growth benefits?

While more research is needed on this topic, it appears that the ketogenic diet may indirectly hold some benefits for hair growth:

It may help reduce androgenetic alopecia

While some think low-carb diets are bad for hair, there are indications that when done correctly, the opposite may be true. The keto diet severely restricts carbs, consuming a lot of which can lead to a higher insulin release (especially when sugary foods or drinks are involved). This, in turn, can increase the level of free (not protein-bound) testosterone available for conversion into DHT [15].

Androgenetic alopecia (female or male pattern baldness) occurs as an enzyme called 5-alpha reductase converts some of your testosterone into a different androgen, called dihydrotestosterone (DHT). DHT binds to specific androgen receptors in your hair follicles, leading to hair miniaturisation and balding. However, lower insulin production from a sugar and carb-free diet makes less testosterone available for DHT conversion, potentially improving the symptoms of your androgenetic alopecia [16].

It may help reduce diabetes-related hair shedding

Obesity is one of the greatest risk factors for developing type 2 diabetes. And once this condition has set in, it has been found to increase the risk of central hair loss in women (especially those of African-American descent) [17].

The keto diet can help you lose weight and, at the same time, reduce your insulin production by cutting back on carbs. This can help you manage your condition better and potentially reduce your risk of diabetes-induced hair loss.

It may help reduce PCOS-induced hair loss

Women with Polycystic Ovary Syndrome (PCOS) experience insulin resistance, which leads to a higher-than-normal secretion of male hormones. This causes hormonal imbalances, negatively affects their ovulation, causes cysts to form on their ovaries and can also lead to or worsen female pattern baldness. However, as discussed above, the keto diet can reduce the need for insulin hyperproduction, indirectly diminishing the levels of free androgens that can bind to hair receptors, causing female pattern hair loss. Thus, it may help reduce pcos-induced hair loss [18].

How soon can you expect hair growth after keto hair loss?

In most cases, you can normally expect to see visible hair regrowth within 3-6 months of onset (as your hair gets used to the diet) or, respectively, once the nutritional deficiency/insufficient calorie intake is corrected. However, keep in mind that hair regrowth is not guaranteed with supplementation after a nutritional deficiency; while rare, there are cases where the hair does not fully grow back [14].

What to do if your hair is not growing back?

If more than 6 months have passed since your hair started falling out and you see no signs of regrowth, that could happen for several reasons:

You still have a nutritional deficiency or an insufficient calorie intake that prevents normal hair growth
You have developed chronic telogen effluvium
Your hair loss may not be related to your keto diet

Whatever the cause, the best thing you can do in this situation is to book a consultation with an experienced hair doctor. They will run the necessary diagnostic trichology tests and offer the best recommendations for your specific situation.

How to prevent keto hair loss

Keto hair loss can’t always be prevented, as it is sometimes merely your over-sensitive hair follicles’ reaction to a significant change in your diet. However, taking the following steps can help reduce your risk of developing this condition:

Avoid crash-style keto

A ketogenic diet is enough to support weight loss even when eating a healthy amount of calories. You don’t need to combine it with restrictive calorie intake, as that can be bad not only for your hair, but for your overall health.

Crash dieting is problematic because it is hard on your body and carries a significant risk of low adherence. Many people are either unable to follow through consistently or succeed in losing considerable weight only to regain it as soon as they start eating normally again (a phenomenon called yo-yo dieting). If you also restrict the food types you are allowed to eat by cutting out carbs while crash dieting, adherence will often drop even further and the risk of nutrient deficiency increases.

Don’t forget that most comfort food contains a significant amount of carbs, and many overweight people use food as a psychological coping mechanism. Only allowing yourself minuscule portions of food and none of the comforting kind can make it very difficult to stick to your diet.

However, eating sufficient of your favourite, well-balanced keto foods can have a protective effect on your health, energy levels, mood and hair health. When trying to lose weight, the aim is normally to reduce your daily recommended calorie allowance by 500-600. So, unless your doctor tells you otherwise, if you are a man, you should aim to intake about 1900 kcal per day, and if you are a woman, your goal should be around 1400 kcal [19].

Build a hair-friendly keto plate

When preparing your keto meal plan, make sure that you are still getting the daily recommended dose of nutrients that keep your body and hair in good health. Be aware of the most important vitamins and minerals your hair needs to grow, and learn about keto-friendly sources to obtain them. And don’t forget to include nutrient-packed, low-carb vegetables, such as leafy greens.

If you aren’t sure about the amount of nutrients your favourite keto-friendly foods contain, here are the average nutritional values for some of the most common (however, please remember that these values can vary widely with food type and source, so don’t forget to check the nutritional info on the packaging of the product you choose):

Beef