Fasting Hair Loss: Definition, Causes And Treatment Options

Medically reviewed by Dr. Zac Hyde M.D.
Written by Our Editorial Team
Last updated

Rising trends in obesity have led to the evolution of newer weight loss techniques. Being associated with numerous adverse complications, invasive weight loss techniques are not favored frequently.

This has led to the development of non-invasive, time-efficient, and diet-friendly weight loss techniques. Intermittent fasting is one of the more popular for restoring human physiology and facilitating effective weight loss. People often use it as an alternative to a diet such as a keto diet and a low carb diet.

However, studies reveal that intermittent fasting may be associated with hair loss. The following sections shed light on can intermittent fasting cause hair loss? If so, then how to prevent hair loss while fasting?


Fasting hair loss is a common health ailment in individuals who fast for shedding excess weight. Apart from its primary application of modulating weight, an intermittent fasting diet is also beneficial for protecting against chronic systemic diseases.

Intermittent fasting improves hormonal concentration in blood and optimizes the secretion of hormones. This promotes normal metabolic reactions and minimizes chemical fluctuations in blood. Intermittent fasting also modulates sleep and motor coordination in an individual.

However, hair loss, hair fall and even baldness can be seen in individuals who do not consume enough calories and are suffering from psychological and/or metabolic stress. Key nutrients supplements and a healthy diet are the key to promote healthy hair growth, despite being associated with genetic determinants.

What is intermittent fasting?

Intermittent fasting, also called time-restricted feeding, is an eating habit characterized by zero to 25% of the caloric intake during regular periods of fasting. Intermittent fasting lasts for about 16 hours for individuals who practice a daily fast.

Other forms of intermittent fasting include minimum calorie intake for 24 hours on every alternate day as well as two days of fasting each week. During a non-fasting period, an individual can consume a normal diet, however, intake shall not surpass more than 125% of the normal limit.

Studies recorded a reduction in muscle mass, waist circumference and body mass index (BMI) in individuals who practice intermittent fasting for weight loss.

How does intermittent fasting work?

how to prevent hair loss while fasting

Intermittent fasting targets the following physiological parameters of the body. These parameters determine the overall health and functioning of most of the body systems.

Circadian rhythm

Intermittent fasting facilitates the body to carry out metabolic functions at optimal times. This improves the pattern of sleep, hormonal secretion, and other homeostatic functions.

The microbiome of the gastrointestinal tract

Intermittent fasting minimizes dysregulation and fluctuations of the gastrointestinal microbiome. These bacteria harvest relatively lesser energy from the diet, regulate calorie intake, and improve obesity-associated inflammation.

Lifestyle behaviors

Intermittent fasting helps regulate optimal energy intake, energy expenditure, and sleep. This improves motor coordination, physical activity, and reduces the risk of systemic disorders.

Intermittent fasting and hair physiology

hormonal imbalance hair loss

An intermittent diet, particularly when not followed correctly, may result in hair loss. Diet is often considered synonymous with starvation, the human body runs out of essential nutrients when the calorie deficit during fasting is not fulfilled during non-fasting periods.

Fasting is also associated with temporary stress and hormonal disruption, as the body is adapting to the change. Even though intermittent fasting has many health benefits like weight loss, it is also directly or indirectly associated with increased hair loss.

Nutrient deficiency and hair loss

fasting detox food

Intermittent fasting induces a state of calorie deficit in an individual. During a non-fasting state, an individual is required to overcome this calorie deficit by consuming an adequate amount of nutrient-dense foods. The diet shall be healthy and well-balanced for better health outcomes and faster weight loss.

The majority of individuals who opt for intermittent fasting overlook their dietary needs and enter into a state of severe nutrient deficiency. Not only does this affect the overall metabolism of the body but also disrupts hair regrowth.

Protein, vitamin, and mineral deficiencies give rise to various forms of hair loss including telogen effluvium, diffuse alopecia, androgenic alopecia, alopecia areata, male pattern hair loss and female pattern hair loss. Following are the important micro and macronutrients like vitamin C along with their regulatory roles in healthy hair growth.


Hair follicular cells divide and proliferate at a greater rate than other human body cells. Ribonucleotide reductase is an important rate-limiting enzyme of DNA synthesis occurring in the rapidly dividing follicular cells.

Iron acts as a cofactor of this enzyme, hence, essential for regulating hair growth. People who are deficient in iron suffer from reduced hair growth and trigger hair loss at an accelerated rate. Vegetarians and other individuals who consume lesser meat are at an increased risk for developing iron deficiency.


This mineral plays a significant regulatory role in protein synthesis and cell proliferation mechanisms. Concerning hair, zinc is a key component of a signaling process responsible for follicular morphogenesis. People with zinc deficiency experience temporary hair loss, brittle hair, and telogen effluvium.

Phytates in legumes and grains bind to zinc and reduce their bioavailability. Hence, people who avoid meat and consume excessive amounts of whole grains and legumes, are more likely to develop zinc deficiency.


Niacin or vitamin B3 deficiency also presents with increased hair loss and bald patches on the scalp.

Polyunsaturated fatty acids (PUFAs)

Essential PUFAs such as omega-3 and omega-6 acids suppress the activity of 5-alpha reductase, thus, reducing the production of dihydrotestosterone (DHT) that is otherwise harmful to hair growth.

These acids also promote the proliferation of cells in hair follicles. People who consume a diet deficient in essential fatty acids may suffer from impaired hair growth and greater hair loss.


Protein is an integral structural component of almost every part of the body including hair. Improper fasting can lead to reduced amino acids and proteins in blood and body tissues. Reduced building blocks or proteins are detrimental for hair health, and lead to significant hair loss.

Stress, fasting and hair loss

Psychological and metabolic stress is commonly observed in individuals who practice intermittent fasting. Telogen effluvium is characterized by metabolic changes and hormonal changes that give rise to excessive hair shedding.

These factors induce most of the hair cells to enter the resting or telogen phase from the growing or anagen phase. Hair growth stops and the hair eventually falls off the scalp.

Fasting, reduced consumption of proteins, and reduced levels of estrogen and thyroid hormones in the blood are closely associated with thinning hair. Psychologic stress may further aggravate hair loss. It is also found that you may experience hair shedding by the use of harsh hair products.

How to prevent hair loss caused by fasting?

fasting hair loss solution

Hair loss from fasting is temporary hair loss. The hair growth cycle will take its place and there is no need for any hair loss treatment.

However, if you want to grow it back faster and keep your hair density, we got your back with the Scandinavian Biolabs Hair Growth Routine.

Made with vegan and naturally-derived ingredients, we guarantee hair growth, or money-back.

Hair Growth Routine | For Men
Hair Growth Routine | For Men
Formulated to combat shedding & signs of balding
Hair Growth Routine | For Women
Hair Growth Routine | For Women
Formulated to combat thinning hair & visible scalp

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Dr. Zac Hyde M.D. is a certified physician (M.D.) who works for Scandinavian Biolabs as a medical consultant. He owns a Health & Wellness blog and has published numerous eBooks. Zac writes articles about medicine, skincare, haircare, and nutrition-related topics. In his free time, he loves to spend his time outside with friends and family.