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Can Hair Dye Cause Hair Loss?

Sara Perkins

Reviewed by Sara Harcharik Perkins, MD

Written by Sheryl George

Published 02/06/2021

Updated 11/15/2023

Many things can lead to hair loss. Sometimes, it’s your genes (thanks, fam), or it can be a nutritional deficiency. And in some cases, it could be the way you treat your hair.

Whether it’s the hairstyles you wear or the haircare products you use, your habits can be a factor in healthy hair growth.

Wondering if hair dye can cause hair loss? This article will walk you through the science and offer ways to protect your hair from damage and future hair loss. 

Let’s first go over what your hair actually is. Each hair is made up of two parts, the hair follicle (the root lying underneath the skin) and the hair shaft (the part that extends out of the scalp).

The hair shaft is made up of a cortex, surrounding cuticle cells, and sometimes, a central medulla. The cortical layer is key in determining components of the hair, like strength, texture and color.

Now think about what you do to your hair. If you color it or heat-style it, you’ve probably noticed that these treatments can affect the appearance of your hair. Also, haircare products like shampoos, hair dyes and hair-straightening products may alter the hair structure, remove lipids and reduce protein.

Dying your hair can be such an expression of who you are — not to mention a fun way to change up your look. Additionally, if you have grays and aren’t ready to embrace the silver fox look, permanent dye is usually a reasonable solution.

If you’ve ever compared virgin hair to heavily bleached hair, you’ve probably noticed how color-treated hair sometimes loses its shine and looks more frizzy since it’s depleted of moisture.

While many people can dye and chemically process their hair without major issues, others aren’t so lucky.

Procedures like hair dying and straightening often come with side effects and health concerns, especially for pregnant women and folks with sensitive scalps. With constant damaging treatments, issues like hair breakage, follicle traction, frizz, contact dermatitis and mutagenicity can arise.

The negative effects of hair dye can be due to:

  • Oxidation from permanent color

  • Ammonia and ethanolamine

  • Bleaching agents

Here’s what to know.

Oxidation From Permanent Dye

Permanent dyes cannot be washed out by shampoos. Instead, they slowly fade over time from weather oxidation (like a t-shirt that loses color after many cycles in the washing machine).

When using a permanent hair dye, an oxidation reaction allows the pigments to get inside the cortex and add color to each hair shaft. This oxidation reaction requires the combination of para dyes — including para-phenylenediamine (PPD), para-toluenediamine and para-aminophenol, known as the primary intermediaries — and hydrogen peroxide.

Ammonia and Ethanolamine

To get passed the cuticle and reach the cortex, your hair product needs to have an alkaline pH. Most often, permanent dyes use ammonia or ethanolamine to increase the pH. Both substances remove the natural cuticle lipid, and this natural cuticle lipid is essential to hair health.

So while permanent dye can last a long time, it can also cause more hair damage compared to non-permanent dyes.

One study noted that monoethanolamine-based dye formulations result in increased damage, as much as 85 percent more than ammonia in the most extreme case. Therefore, ammonia may be a less damaging option over a harsher alkalizer.

Bleaching Agents

Do you love getting highlights or lightening your naturally dark locks? This can be particularly harsh on the hair shaft.

The bleaching process occurs in the pH range of 8 to 10 and needs ammonia or ethanolamine and hydrogen peroxide to occur. Bleaching agents can cause significant damage to hair, which is why overly highlighted hair can look dull and damaged as the cuticle is stripped.

Chemical bleaches weaken the cell membrane complex of the hair, effectively dissolving proteins in areas rich in cysteine and leading to a lifted cuticle scale as well as protein loss.

In layman’s terms, it means you’re likely noticing rough-looking hair with breakage or split ends. Patients with alopecia or sensitive hair are recommended to avoid bleaching, as it can damage already-fragile hair.

The science indicates that it’s pretty rare to have hair loss from dying or coloring hair.

Hair dye reactions are usually self-diagnosed. Epidemiological studies found that between 0.1 and 1 percent of patients are sensitized to dyes containing para-phenylenediamine (PPD). This ingredient seems to be what causes an allergic reaction in some.

When having a reaction to hair dye containing PPD, the most frequent symptoms tend to be erythema (redness) of the face, scalp and ears following use. Severe facial and scalp dermatitis with PPD has been reported in several cases, with symptoms of edema, suppuration and ulceration of the face, scalp and eyelids.

But keep in mind, reports of hair loss due to hair dyes containing PPD are rare. There were only two reported cases due to a PPD allergy associated with dermatitis in a consumer-based study.

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Step away from the dye — easy…easy. While your roots may signal a need to touch up every four to six weeks, your hair shaft may disagree if it’s easily damaged.

Speak to your hairstylist to figure out solutions that may help you go longer between appointments. For instance, balayage and ombre hair allow a more lived-in look where the roots can intentionally be darker. If you feel like your hair is damaged or thinning, you may not want to be going for aggressive treatments on the regular.

If you’re dying your hair because you’re going gray, consider letting yourself rock that silver. Seriously, the silver fox look isn’t just for George Clooney. But if you have premature graying (before the age of 30), consider the potential causes.

Certain autoimmune disorders, such as pernicious anemia and autoimmune thyroid disease, have been linked to premature hair graying (PHG). A link between smoking and gray hair (as well as smoking and hair loss) has been reported in both men and women.

It’s not totally understood how smoking affects hair. However, some believe that since smoking generates huge amounts of reactive oxygen, it leads to increased oxidative stress, which can affect your hair.

Listen, we aren’t trying to sound like your parents — you can have fun out there as long as you protect yourself, kay?

But as mentioned above, dying and bleaching can damage the hair shaft. You can keep dyed or bleached hair healthy by making sure you’re giving it TLC with the right haircare products. 

Conditioner is going to be your best friend, and hair masks will also join this crew. Conditioners are used to decrease friction, seal the cuticle, detangle the hair, minimize frizz, add shine and improve manageability. Bleached and dyed hair tend to be more porous, so they’re thirsty for moisture. 

Make sure to use a conditioner after every wash. Additionally, add in a deep hydrating mask weekly to really give your hair an extra boost of moisture.

Post-shower, be gentle when combing your hair strands. Also, since colored and bleached hair already has a more fragile cuticle, take it easy on heat styling. Hot tools like your curling iron or blow dryer can further zap moisture and cause more damage, so keep that temperature low, low, low.

Think your hair is fried? Learn more about how to help repair chemically damaged hair in this excellent guide.

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It’s highly unlikely that coloring your hair will lead to hair loss or balding. After all, most women color their hair with no adverse reactions at all.

That said, hair dyes and bleaching agents can cause damage to your hair.

Remember the following to keep healthy hair intact:

  • Stretch hair color appointments so you’re not dying and bleaching hair constantly, causing stress on the hair cuticle. 

  • Use conditioners and other hydrating hair products to fend off damage.

  • Try your best to live a healthy lifestyle, including easing up on cigarettes, which have been linked to premature graying and hair loss. 

If you’re experiencing hair thinning or loss, it may be a sign of other issues. Talk to your healthcare provider to rule out other possible causes.

You can start your consultation now from your own home or explore science-backed hair loss treatments from Hers.

6 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Hoover, E., Alhajj, M., & Flores, J. L. (2022, July 25). Physiology, Hair - StatPearls. NCBI. Retrieved from
  2. Bailey, A. D., Zhang, G., & Murphy, B. P. (n.d.). Comparison of damage to human hair fibers caused by monoethanolamine- and ammonia-based hair colorants. PubMed. Retrieved from
  3. Reis Gavazzoni Dias,, M. F., Loures, A. F., & Ekelem, C. (2021, December 27). Hair Cosmetics for the Hair Loss Patient - PMC. NCBI. Retrieved from
  4. Ishida, W., Mekino, T., & Shimizu, T. (2011, April 11). Severe Hair Loss of the Scalp due to a Hair Dye Containing Para phenylenediamine. NCBI. Retrieved from
  5. Zayed, A. A., Shahait, A. D., Ayoub, M. N., & Yousef, A. (n.d.). Smokers’ hair: Does smoking cause premature hair graying? NCBI. Retrieved May 22, 2023, from
  6. Reis, M. F. (2015). Hair Cosmetics: An Overview - PMC. NCBI. Retrieved from

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Sara Harcharik Perkins, MD

Sara Harcharik Perkins, MD, FAAD is a board-certified dermatologist and Assistant Professor in the Department of Dermatology at the Yale School of Medicine. She is the director of the Teledermatology Program, as well as the Associate Program Director of the Yale Dermatology Residency Training Program. Her research focuses on telemedicine and medical education. Her practice includes general medical dermatology, high-risk skin cancer, and procedural dermatology.

Dr. Perkins completed her undergraduate education at the University of Pennsylvania and obtained her medical degree at the Icahn School of Medicine at Mount Sinai. She completed her medical internship at the Massachusetts General Hospital, followed by residency training in dermatology at Yale University, after which she joined the faculty.

Dr. Perkins has been a member of the Hims & Hers Medical Advisory Board since 2018. Her commentary has been featured in NBC News, Real Simple, The Cut, and Yahoo, among others.


  • Ahmad, M., Christensen, S. R., & Perkins, S. H. (2023). The impact of COVID-19 on the dermatologic care of nonmelanoma skin cancers among solid organ transplant recipients. JAAD international, 13, 98–99.

  • Ahmad, M., & Perkins, S. H. (2023). Learning dermatology in medical school: analysis of dermatology topics tested in popular question banks. Clinical and experimental dermatology, 48(4), 361–363.

  • Belzer, A., Leasure, A. C., Cohen, J. M., & Perkins, S. H. (2023). The association of cutaneous squamous cell carcinoma and basal cell carcinoma with solid organ transplantation: a cross-sectional study of the All Of Us Research Program. International journal of dermatology, 62(10), e564–e566.

  • Ahmad, M., Marson, J. W., Litchman, G. H., Perkins, S. H., & Rigel, D. S. (2022). Usage and perceptions of teledermatology in 2021: a survey of dermatologists. International journal of dermatology, 61(7), e235–e237.

  • Asabor, E. N., Bunick, C. G., Cohen, J. M., & Perkins, S. H. (2021). Patient and physician perspectives on teledermatology at an academic dermatology department amid the COVID-19 pandemic. Journal of the American Academy of Dermatology, 84(1), 158–161.

  • Belzer, A., Olamiju, B., Antaya, R. J., Odell, I. D., Bia, M., Perkins, S. H., & Cohen, J. M. (2021). A novel medical student initiative to enhance provision of teledermatology in a resident continuity clinic during the COVID-19 pandemic: a pilot study. International journal of dermatology, 60(1), 128–129.

  • Cohen, J. M., Bunick, C. G., & Perkins, S. H. (2020). The new normal: An approach to optimizing and combining in-person and telemedicine visits to maximize patient care. Journal of the American Academy of Dermatology, 83(5), e361–e362.

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