Myth: Daily washing causes hair loss.

Many people worry that washing their hair too often can cause hair loss. But is that really true? Let’s break it down.

What Happens When You Wash Your Hair?

Your hair contains natural oils (lipids) that help keep it strong and healthy. These oils include:

• Water-repellent lipids (like squalene and wax esters) that keep moisture from escaping.

• Water-neutral or water-loving lipids (like fatty acids and cholesterol) that help maintain the hair’s structure.

Shampoos contain surfactants, which help remove dirt, oil, and buildup. Two common surfactants are sodium laureth sulfate and cocamidopropyl betaine. While these ingredients effectively clean the hair, lab studies show that they can strip the hair of both surface and internal lipids (1). Cocamidopropyl betaine is milder, but when combined with other surfactants and friction (like scrubbing), it can still contribute to lipid loss (1).

Hair Washing and Hair Damage

Although washing hair may cause structural damage to the exposed hair shaft (2), it does not inherently cause hair loss.  In fact, increased washing frequency can lead to improved perceptions of hair quality, including reduced brittleness and enhanced overall satisfaction with the condition of your hair. 

Does Frequent Washing Damage Hair?

Although lab studies show some lipid loss, real-life studies tell a different story. Research analyzing shampoo wash frequency found that daily washing actually improved scalp and hair condition and did not show any harmful effects on hair health (3).

It’s worth noting that the aforementioned studies were conducted in Asian populations, an ethnic group that typically has a higher hair lipid content. This means they may tolerate daily washing better than other hair types. Different hair textures and oil production levels may lead to different reactions, so hair washing frequency should be adjusted based on individual needs.

Does Washing Hair Cause More Shedding?

Some people notice more hair shedding when they wash their hair, but this doesn’t mean the hair loss is caused by the shampoo or act of washing.

A clinical study on Brazilian individuals with hair loss conditions (telogen effluvium and androgenetic alopecia) found that a shampoo and lotion combination actually reduced hair shedding after washing (4). This suggests that washing hair doesn’t contribute to hair loss—it may actually help manage shedding instead.

People with conditions like telogen effluvium and androgenetic alopecia may see more hair shedding during washing, but this is due to the underlying condition, not the act of washing  itself (5). So, rather than causing hair loss, daily washing may help reduce the buildup of shed hairs.

Understanding Normal Hair Shedding

We normally shed between 50–150 hairs per day, and hair washing merely helps remove loose hairs that would have fallen out naturally (6). This may give the appearance that washing hair causes hair loss because more hair is visualized shedding while washing. If you are already anxious about hair loss, this can be perceived as irregular.  However, this is often due to accumulated loose hairs that are ready to shed anyway in the near future, rather than an actual increase in hair loss. As hair grows through its lifecycle, it is anchored within the hair follicle below the skin’s surface.  Damage to the external hair shaft (hair above the skin surface) may lead to easy breakage or undesirable texture changes, but does not often impact the attachment of the hair within the follicle.  This is mostly impacted by biological processes in the scalp, underneath the skin surface.    

Final Thoughts

There is no strong scientific evidence that daily hair washing causes hair loss. While frequent washing might change how your hair feels or looks, it does not appear to affect hair growth. Instead, washing helps remove loose hairs that were already shedding naturally.

Concerns about hair loss from washing are often due to a misunderstanding of normal shedding—and, understandably, anxiety for those experiencing hair loss conditions. If you’re worried about hair loss, it’s always a good idea to consult a professional for personalized advice. You can obtain an online consultation from Bridge Dermatology if you currently reside in California, Connecticut, Illinois, or Nebraska.

Dr. Ryan M. Trowbridge, MD, MS, MA

DermMythBuster

P.S. Have you come across any new or conflicting research on this topic? Please share—I’d love to explore it further with you!

Citations:

1. Song SH, Lim JH, Son SK, Choi J, Kang NG, Lee SM. Prevention of lipid loss from hair by surface and internal modification. Sci Rep. 2019 Jul 8;9(1):9834. doi: 10.1038/s41598-019-46370-x. PMID: 31285480; PMCID: PMC6614367.

2. Tate, M. L., Kamath, Y. K., Ruetsch, S. B., & Weigmann, H.-D. (1993). Quantification and prevention of hair damage. Journal of the Society of Cosmetic Chemists, 44, 347–371. Retrieved from https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=f480283dba7bc7bfecbafebcac2901c614ca6165

3. Punyani S, Tosti A, Hordinsky M, Yeomans D, Schwartz J. The Impact of Shampoo Wash Frequency on Scalp and Hair Conditions. Skin Appendage Disord. 2021 Apr;7(3):183-193. doi: 10.1159/000512786. Epub 2021 Feb 15. PMID: 34055906; PMCID: PMC8138261.

4. Anzai A, Pereira AF, Malaquias KR, Guerra LO, Mercuri M. Efficacy and safety of a new formulation kit (shampoo + lotion) containing anti-inflammatory and antioxidant agents to treat hair loss. Dermatol Ther. 2020 May;33(3):e13293. doi: 10.1111/dth.13293. Epub 2020 Mar 20. PMID: 32134172.

5. Li X, Wang X, Wang C, Zhang J, Zhou C. Hair Shedding Evaluation for Alopecia: A Refined Wash Test. Clin Cosmet Investig Dermatol. 2022 Jan 25;15:117-126. doi: 10.2147/CCID.S347898. PMID: 35115799; PMCID: PMC8801509.

6. Sinclair R. Hair shedding in women: how much is too much? Br J Dermatol. 2015 Sep;173(3):846-8. doi: 10.1111/bjd.13873. Epub 2015 Aug 19. PMID: 25914081.