Is Intermittent Fasting Secretly Sabotaging Your Hair?

Intermittent fasting is all the rage these days on social media, hailed for everything from weight loss to reduced risk for Alzheimer's disease and type 2 diabetes. However, an increasing number of people are worried about why their hair is falling out. If you’ve noticed changes in your hair since starting a fasting regimen, you’re not imagining it. New research suggests that fasting could impact the delicate biological processes that support healthy hair growth, particularly if you’re not focusing on the right nutritional support. 

Science Uncovers An Important Connection

A recent ‘Nature’ news article and a remarkable clinical trial published in ‘Cell’ reveal some surprising insights into how the body prioritises energy during fasting. Researchers have found that prolonged periods without food may trigger the body to divert energy away from non-essential functions, like hair growth, to conserve resources for vital organs and systems.1,2

At the centre of this process are hair follicle stem cells, which are responsible for regenerating hair. These cells require a steady supply of energy and nutrients to stay active. When the body enters a fasting state, the metabolism shifts, reducing the activity of these stem cells and potentially slowing down hair growth or even leading to increased shedding.3

This may be especially relevant for women, whose hormonal balance is more sensitive to dietary changes. However, men aren’t off the hook completely. Studies show that damage to hair follicles is not exclusive to women; men are also affected by cellular responses to metabolic stress from fasting.2 To make matters worse, if you combine fasting with low-calorie intake or micronutrient deficiencies, you may be creating an environment that is detrimental to scalp and hair health.

How Does Fasting Affect Your Hair Long-Term?

Hair goes through natural cycles of growth, rest, and shedding. But when the body is under nutritional stress, these cycles can become disrupted. According to research, one of the mechanisms observed during fasting is that stem cells in the hair follicles pause their activity.2 The longer they remain inactive, the harder it becomes to restart the growth phase. Eventually, this could result in: 

·        Thinner hair overall

·        More hair on your brush or in the shower

·        Slower regrowth after shedding

·        A more visible scalp, especially around the parting

Healthy Hair Needs Daily Nutritional Support

While short-term fasting may not cause noticeable issues, ongoing or aggressive fasting strategies may increase the risk of nutrient depletion. If you’re trying intermittent fasting, it’s important to ensure your eating window includes nutrient-dense foods that support hair structure and scalp health. Your meals should include: protein, collagen, omega-3 essential fatty acids (EFAs), biotin, zinc, selenium, riboflavin, and vitamin C.

Vitamin C, for example, contributes to collagen formation for normal skin function; this includes the scalp, which serves as the foundation for healthy-looking hair. It also helps to protect cells from oxidative stress, a key factor in ageing and inflammation.³ Vitamin D also plays an important role in hair health as it contributes to the process of cell division, a fundamental mechanism involved in the normal turnover and renewal of cells, including those within the hair follicle. 

In addition to this, nutrients like biotin, zinc, selenium, EFAs and riboflavin play recognised roles in maintaining normal skin and hair, as well as supporting processes such as cell division, protection from oxidative stress, and normal energy metabolism.

Dietary  Recommendations 

Intermittent fasting may offer some valuable health benefits, but it shouldn’t come at the cost of your hair. If you're noticing increased shedding, dullness, or thinning, it may be time to review your routine. Formulate a diet plan that includes the essential nutrients listed in the table below. 

Choose Supplements That Make a Difference

Although healthy, balanced nutrition is ideal, it's not always possible to follow a perfect diet, particularly within the restricted eating window that intermittent fasting requires. This is where targeted supplementation can help fill nutritional gaps and ensure your hair follicles have consistent access to the nutrients they need. 

Vitamin C deserves special mention here. It contributes to normal collagen formation and helps protect cells from oxidative stress, two processes that are fundamental to scalp and hair health. Choosing a formula that combines multiple buffered forms of vitamin C can help ensure effective absorption without upsetting the stomach, making it a practical and gentle option for daily use.

 For broader nutritional coverage, a comprehensive multivitamin and mineral complex is an efficient way to ensure you're getting the full spectrum of hair-supportive nutrients,  including biotin, zinc, selenium, riboflavin, and vitamin D in a single daily supplement. When fasting narrows your eating window, having this kind of nutritional safety net in place can make all the difference to the health of your hair and scalp over the long term. 

A Complementary Intervention for Hair Support

There’s no reason why intermittent fasting shouldn’t work in your favour if you are using your eating window sensibly and filling it with hair & scalp healthy nutrients. You might also find that, alongside nutrition, a gentle therapy like reflexology could also play a helpful role.

Reflexology involves applying pressure to specific points on the hands or feet and has been linked in early research to improvements in hair quality, particularly in women with alopecia recovering from chemotherapy.⁵ Adding this kind of holistic support to your routine could be a simple yet valuable part of your hair care strategy.

Written by: Jacqueline Newson BSc (Hons) Nutritional Therapy

References

1.   Trafton, A. (2024). “Why fasting might cause hair loss.” Nature.

2.  Chen, Han et al. Intermittent fasting triggers interorgan communication to suppress hair follicle regeneration. Cell, 2025; Volume 188, Issue 1, 157 - 174.e22

3.  Chen et al. (2024). “Fasting suppresses hair follicle stem cell activation.” Cell.

4.  EFSA Register: Vitamin C contributes to normal collagen formation and protection of cells from oxidative stress.

5.  Ghavami H, Arjomand L, Radfar M, Khalkhali Hr. Effects of Reflexology Massage on Hair Regrowth After Chemotherapy-induced Alopecia Among Women with Cancer: A Randomised Clinical Trial. Bezmialem Science. 2020 Jul;8(3):215-221. doi:10.14235/bas.galenos.2019.3473.