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Does Bleaching Your Hair Damage It?

Vicky Davis

Reviewed by Vicky Davis, FNP

Written by Our Editorial Team

Published 10/26/2022

Updated 10/26/2021

Thinking about bleaching your hair? If so, there are a few things you should know. 

Most importantly, yes, it does damage your hair. But that doesn’t mean you can’t do it. You just need to know how to add nourishment back into your strands. 

That’s what we’re digging into today. What, exactly, does bleach do to damage your hair? Once the damage is done, how can it be repaired? What tips and tricks do the pros recommend? 

How Bleach Damages Your Hair

If you’re thinking of bleaching your hair, chances are your goal is to lighten it — and bleach is a very effective way of doing that. Bleach is a fast way to remove pigment from your hair. 

When applied to your hair, bleach opens the hair shaft and breaks down pigment molecules. When you wash the bleach out, those pigments go with it and leave you with lighter hair. 

At the same time, it weakens the hair by breaking down the fatty acids on the shaft. This can leave hair feeling dry and brittle.

One study done on rats found that after bleaching their hair, it was weakened. It is, of course, worth noting that because this study was conducted on rats, it may not be exactly true for humans. 

However, we think it’s safe to assume the results would probably be at least similar in humans. 

Another study used a microscope to look at the hair shaft after bleaching and found there was damage to the structure of the hair. 

If you do decide to bleach your hair, it’s important to know ways you can add moisture and shine back into your strands — since those are the things bleach can take away. 

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How to Treat Bleached Hair

Since bleach strips important nutrients and proteins out of your hair, you’ll want to incorporate some habits into your routine that support hair health. 

Use the Right Shampoo and Conditioner

If you have bleached strands, the types of products you use matter. Consider using a shampoo and conditioner formulated to thicken hair. 

Her’s thickening shampoo is made with a natural ingredient called saw palmetto. Research suggests it can potentially reduce hair loss. 

One study, for instance, compared the hair loss medication finasteride with saw palmetto. Finasteride was found to be most effective in reducing hair loss, but saw palmetto was also effective. 

Oh, and don’t skip the conditioner! The whole point of a conditioner is to replace moisture. They can also increase shine and volume.

There are a variety of conditioners to choose from — from ones intended for daily use, to leave-in treatments and deep conditioning masks

Using one after you shampoo is good for maintenance. Deep conditioners are more concentrated and are intended to be left on your hair for a longer period of time before washing out. 

Interested in a leave-in conditioner? They are meant to be applied to wet hair after a shower to moisturize and detangle hair. 

Focus on Omega-3 Fatty Acids

Remember how we said bleach strips fatty acids from your hair? Making sure you’re getting enough omega-3 fatty acids can help boost hair health.

One study looked at 120 women over the course of six months and found that omega-3 and omega-6 — notable antioxidants — can be useful in improving hair density.

A good way to incorporate these into your routine is through diet. Foods that contain them include:

  • Fish (like salmon, mackerel and tuna) 

  • Nuts and seeds (like chia seeds and walnuts) 

  • Plant seed oil (like flax seed oil) 

If you have a hard time getting enough into your diet, you can consider an omega-3 supplement. 

Embrace Oils

From cooking to beauty benefits, coconut oil is often praised for its many uses. 

When it comes to using it in your hair care regime, it is known to have antibacterial and antifungal properties, both of which can help protect your strands. 

Coconut oil also is full of fatty acids — and you already know those promote healthy hair.

Another benefit: it penetrates deep into the hair shaft, which can help prevent breakage.

Another oil you should know about is argan oil, which is also rich in fatty acids. This type of oil is touted as a worthy adversary against dry hair.

Consider Biotin

Recently, biotin supplements have become all the rage. They’re all over social media, with influencers swearing that they make hair healthier. But do they? 

There’s simply not enough research to support these claims. Beyond that, you probably don’t need a biotin supplement, as you most likely get enough from your diet. 

All of this said, there is early research linking biotin to hair growth.

Try Collagen

Here’s another supplement you’ve likely seen hocked on Instagram. Collagen is a protein that is naturally present in mammals. 

It’s hugely important in skin, hair, muscles, nails and connective tissue. 

It may surprise you to know that it actually makes up 30 percent of your body’s protein mass. 

But, like with biotin, a heck of a lot more research is needed to support whether or not collagen supplements can boost hair health. See more details in our collagen and hair guide.

There was one small study done that centered around 15 women who all reported having thinning hair. 

Some of the women were assigned a collagen supplement, others were given a placebo. All the women took these supplements twice a day for six months. 

After half a year, the women who took collagen said they noticed that their hair was shinier.

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Before You Bleach

If you’re looking to go from dark hair to blonde hair, you’ll have to use bleach. Or perhaps you want to lighten your hair so you can then dye it a bold color — hello, blue strands. Whatever your reason, you should know that using hair bleach can damage your locks. 

When you use bleach, this chemical process seeps into hair follicles and can make your hair dry and brittle. 

The level of damage this can do varies and really depends on the condition of your hair and your hair type to begin with. 

Because of this, you’ll want to give bleached hair a good deal of TLC. That can mean everything from using a hair mask (try one for color-treated hair!) on the regular to considering various supplements. 

It’s also worth noting that if you do want to bleach your hair, you should go to a professional hair stylist. They will know how to prevent permanent damage during the hair bleaching process. 

15 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. Feitman, R., (2015). Why Bleaching wrecks your hair (and how to make it better). Retrieved from ​​
  2. Jeong, M., Lee, C., Jeong, W., et al., (2010). Significant damage of the skin and hair following hair bleaching. J Dermatol. Retrieved from
  3. Imai, T., (2011). The influence of hair bleach on the ultrastructure of human hair with special reference to hair damage. Okajimas Folia Anat Jpn. Retrieved from
  4. Rossi, A., Mari, E., Scarno, M., et al. (2012, October). Comparative Effectiveness and Finasteride Vs Serenoa Repens in Male Androgenetic Alopecia: A Two-Year Study. International Journal of Immunopathology and Pharmacology, Volume 25, Issue 4, pages 1167-1173. Retrieved from
  5. D’Souza, P., Rathi, S., (2015). Shampoos and Conditioners: What a Dermatologist Should Know? . Indian Journal of Dermatology. Retrieved from
  6. Dias, M., (2015). Hair Cosmetics: An Overview. International Journal of Trichology. Retrieved from
  7. Le Floc’h, C., Cheniti, A., Connetable, S., (2015). Effect of a nutritional supplement on hair loss in women. J Cosmet Dermatol. Retrieved from
  8. Omega-3 Fatty Acids. National Institute of Health. Retrieved from
  9. Widianingrum, D., Noviandi, C., Salasia, S., (2019). Antibacterial and immunomodulator activities of virgin coconut oil (VCO) against Staphylococcus aureus. Heliyon. Retrieved from
  10. Ogbolu, D., Oni, A., Daini, O., Oloko, A., (2007). In vitro antimicrobial properties of coconut oil on Candida species in Ibadan, Nigeria. J Med Food. Retrieved from
  11. Hanana, M., Mezghenni, H., Ayed, R., et al., (2018). Nutraceutical potentialities of Tunisian Argan oil based on its physicochemical properties and fatty acid content as assessed through Bayesian network analyses. Lipids in Health and Disease. Retrieved from
  12. Vilareal, M., Kume, S., Bourhim, T., et al., (2013). Activation of MITF by Argan Oil Leads to the Inhibition of the Tyrosinase and Dopachrome Tautomerase Expressions in B16 Murine Melanoma Cells. Evid Based Complement Altern Med. Retrieved from
  13. Ablon, G. (2015). A 3-Month, Randomized, Double-Blind, Placebo-Controlled Study Evaluating the Ability of an Extra-Strength Marine Protein Supplement to Promote Hair Growth and Decrease Shedding in Women with Self-Perceived Thinning Hair. Dermatology Research and Practice. Retrieved from
  14. Glynis, A., (2012). A Double-blind, Placebo-controlled Study Evaluating the Efficacy of an Oral Supplement in Women with Self-perceived Thinning Hair. The Journal of Clinical and Aesthetic Dermatology. Retrieved from
  15. Ricard-Blum, S.. (2011, Jan). The Collagen Family. Cold Spring Harbor Perspectives in Biology, 3(1): a004978. 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.

Vicky Davis, FNP

Dr. Vicky Davis is a board-certified Family Nurse Practitioner with over 20 years of experience in clinical practice, leadership and education. 

Dr. Davis' expertise include direct patient care and many years working in clinical research to bring evidence-based care to patients and their families. 

She is a Florida native who obtained her master’s degree from the University of Florida and completed her Doctor of Nursing Practice in 2020 from Chamberlain College of Nursing

She is also an active member of the American Academy of Nurse Practitioners.

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