The Independent Pharmacy

Does Intermittent Fasting Affect Hair Loss

Scott McDougall
Scott McDougallMPharmDirector & Registered Manager

Reviewed on 6 Oct 2023

With intermittent fasting growing in popularity as a health and weight loss trend, you might be wondering if periods of fasting could negatively impact your hair. And if you’re already experiencing hair loss or faced the challenge in the past, you might be even more wary of trying something new.

At The Independent Pharmacy, we understand that hair loss can be deeply personal and distressing for many, affecting not just appearance but also self-esteem and emotional well-being. We care about your well-being and want to support you along the way.

To make sure that you’re safe, you need to understand what intermittent fasting is and how it can affect you. It involves alternating intervals of eating and fasting, most typically in patterns like 16/8 - fasting for 16 hours per day and restricting eating to an 8-hour window. Other common approaches are 5:2 fasting, which restricts calories for two non-consecutive days per week, or alternate-day fasting. Those who support intermittent fasting often cite benefits like weight loss, heart health, and anti-ageing.

But if you already have hair concerns, it’s only natural to wonder if intermittent fasting might further disrupt the delicate balance of hair growth and the essential nutrients it needs.

In this guide, we’ll help you understand the link between intermittent fasting and your hair health so you can make the right choice.

What Is Intermittent Fasting?

Intermittent fasting (IF) is an eating pattern that involves cycling between periods of fasting and eating. It differs from normal eating patterns, where meals are consumed throughout the day.

Some of the most popular IF approaches include:

  • 16/8 method - This involves a 16-hour fasting window and an 8-hour eating window. For example, skipping breakfast and only eating between 12 pm - 8 pm.
  • 5:2 diet - Eating normally 5 days per week, then limiting calories to 500-600 for two non-consecutive days.
  • Eat-stop-eat - 24-hour fasts once or twice per week, with no calorie restriction on other days.

IF has surged in popularity due to purported benefits like better weight control, cardiovascular health, and prevention of type 2 diabetes. Other advantages include improved focus and cellular repair from autophagy (the body’s natural cleanup process).

However, it’s worth noting that everyone’s body reacts differently, and some might experience challenges, especially when first starting intermittent fasting. These can include dizziness, headaches, and difficulty sleeping. Hunger and reduced energy are also common initially.

Intermittent Fasting and Nutritional Deficiencies

A genuine worry for many is whether intermittent fasting, with its periods of reduced food intake, might inadvertently deprive them of the vital nutrients their hair needs. Many vitamins [link to the piece What are hair loss vitamins] and minerals play key roles in maintaining healthy hair growth. Not consuming enough of them can negatively impact the hair follicles.

Some nutrients that are especially important for hair health include:

  • Iron - Required for ferritin synthesis that promotes hair growth. Deficiency causes anaemia and excessive shedding.
  • Zinc - Zinc is important for protein synthesis and DNA/RNA production in hair follicles. Deficiency has been linked to alopecia.
  • Biotin - Biotin is used for keratin production, which hair is made of. Deficiency can lead to brittle hair.
  • Protein - Amino acids provide the building blocks for hair growth. Too little protein can impair production.
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During the fasting periods, intake of these key nutrients decreases. For some, prolonged calorie restriction makes it challenging to meet daily needs. This can contribute to hair thinning, slower growth, excessive shedding, and impaired regeneration.

However, these effects are unlikely with moderate calorie reduction for brief periods. Careful nutrient planning around fasting can help maintain healthy hair.

Stress, Hormones, and Hair Loss

In addition to nutrition, intermittent fasting can affect hormones and stress pathways in ways that impact hair health.

When the body is in a fasted state, this triggers a mild stress response. The adrenal glands produce more cortisol, the body’s primary stress hormone. When cortisol levels rise, our body starts using its stored proteins and fats for energy.

While this is a natural response to fasting, chronic stress and consistently high cortisol can have negative effects. It disrupts the hair growth cycle by preventing follicles from absorbing enough nutrients to sustain growth.

Intermittent fasting might affect certain hormones in our body, like insulin and thyroid hormones, which can, in turn, impact our hair health. However, research on this is limited. The hormonal effects likely depend on the individual, fasting duration, and other lifestyle factors.

In general, minor short-term hormone fluctuations are well-tolerated. However, those prone to hormone-related hair loss should take a cautious approach to intermittent fasting and monitor for increased shedding.

Benefits of Intermittent Fasting for Hair Health

While intermittent fasting can potentially impact hair due to nutritional deficits and hormonal shifts, some benefits have also been suggested.

One is improved circulation. During the fasted state, blood flow increases throughout the body as a survival mechanism. More blood circulating to the scalp may nourish hair follicles with oxygen and nutrients.

Cellular renewal through autophagy is another proposed benefit. Autophagy is like a cleaning process where our body gets rid of old and damaged cells. Think of it as a ‘spring cleaning’ for our cells. This may promote healthier hair by reducing inflammation and oxidative stress.

Intermittent fasting may also balance key hormones related to growth and metabolism. When we fast, our body’s insulin levels usually drop, and growth hormone levels go up. Both of these changes can affect our overall health. This hormonal environment encourages nutrients to be used for regenerative processes like hair production.

However, current research is limited. More studies are needed to substantiate fasting as an effective approach for improving hair health. But these potential upsides make it worthwhile to experiment under medical supervision.

Potential Risks and How to Mitigate Them

While intermittent fasting may offer some benefits, potential drawbacks should also be considered:

  • Nutrient deficiencies - Monitor protein/nutrient intake and take supplements if needed. Time fasting periods so nutrient-dense meals can be consumed.
  • Hormonal changes - Note any hormonal symptoms like fatigue, mood changes, or altered cycles that could relate to hair thinning. Adjust fasting routine if hair loss increases.
  • High stress - Take care to manage stress levels with relaxation techniques. Excess cortisol can impair hair growth.
  • Transition effects - Headaches, dizziness, insomnia, and hunger pangs often subside after adapting to intermittent fasting. But if negative effects persist, talk to your doctor.
  • Detrimental eating habits - Binge eating after fasting can sabotage hair health goals. Focus on nutritious foods in proper portions during eating periods.

Being aware of these risks allows appropriate precautions to be taken. Getting enough protein, essential fatty acids, vitamins, and minerals is key. Seek professional guidance to ensure nutritional needs are met. With a balanced intermittent fasting plan tailored to the individual, benefits may be obtained without sacrificing hair health.

Understanding Hair Growth and Factors Affecting It

To better understand the potential effects of intermittent fasting on hair, it helps to know how hair growth normally occurs and what influences it.

Hair goes through three phases as part of the growth cycle:

  • Anagen phase - Active growth phase that lasts 2-7 years. Accounts for 85-90% of hair at a given time.
  • Catagen phase - Transitional phase lasting 2-3 weeks. Hair detaches from the blood supply, and growth stops.
  • Telogen phase - Resting phase of 2-3 months. Around 10-15% of hair is in this phase, waiting to shed.

Many things, both inside our body and in our environment, can interfere with how our hair grows, leading to hair thinning or more hair falling out:

  • Nutrition - Deficiencies in protein, vitamins, iron, zinc and other nutrients impair hair follicle function.
  • Stress - High cortisol causes premature shifting of hair into the telogen resting phase.
  • Hormones - Thyroid disorders, high androgens, and menopause lead to hormonal hair loss.
  • Medications - Drug side effects like chemotherapy.
  • Aging - Hair follicles shrink, and growth cycles shorten.
  • Scalp health - Dandruff, infections, dryness or inflammation can inhibit healthy hair.

Understanding one’s individual hair growth cycle and risk factors allows steps to be taken to maximise hair health when fasting.

People Also Ask

Can fasting cause hair loss?

Yes, intermittent fasting may contribute to excessive hair shedding and thinning in some cases. Drastic calorie restriction can lead to nutritional deficits, while effects on cortisol, growth hormone and thyroid hormones influence hair’s growth cycle. However, minor nutrient changes and short-term hormonal shifts are well-tolerated if the fasting approach is balanced.

Does hair loss from fasting grow back?

With temporary hair loss from intermittent fasting, normal regrowth should occur after transitioning back to a regular diet that provides sufficient nutrition. However, severe caloric restriction for extended periods can cause permanent damage to hair follicles.

Can starvation cause hair thinning?

Starvation and extremely low-calorie diets for long periods will likely impact hair. This deprives follicles of vital nutrients, proteins, fats, vitamins and minerals needed for healthy hair growth. However, controlled intermittent fasting is not the same as long-term starvation.

What is hair fasting?

“Hair fasting” refers to abstaining from cutting, colouring, or chemically treating hair for a period of time. It does not involve food calorie/diet fasting. The theory is that avoiding any hair processing will allow natural growth and healing. However, hair fasting itself does not influence actual hair health or growth cycles.


Intermittent fasting offers intriguing potential benefits but also carries risks when it comes to hair health. The impact can vary dramatically based on the individual’s unique biology and fasting protocol.

For those who’ve faced the emotional toll of hair loss or have battled nutritional challenges, it’s especially important to approach intermittent fasting with care and mindfulness. Monitor hair and nutrient intake closely when first adopting intermittent fasting. Seek personalised guidance from a healthcare provider on mitigating risks.

With a balanced approach, fasting may improve circulation, cellular regeneration, and hormone balance in ways that benefit hair. However, more rigorous controlled studies on various fasting regimens are still needed. Initial research shows promise, but optimal intermittent fasting plans must be refined for long-term hair health.

Remember, you’re not alone on this journey. Prioritising your nutritional needs, finding ways to manage stress, and being attentive to your body’s signals are essential steps. And always know it’s okay to seek support when needed. Address these issues promptly if they arise. While intermittent fasting is surging in popularity for weight loss and health, its effects on human hair remain to be fully elucidated.

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