The L’Oréal Lawsuit and the Dangers of Hair Straighteners

loreal lawsuit

Permanently straightening curly hair is not easy. Nature holds the curls in the protein structure of the hair shaft, and straightening the shaft involves chemically breaking those bonds. Permanently curling straight hair is similarly difficult. That’s why harsh chemicals are involved in both curling and straightening hair.

A lawsuit was filed against L’Oréal in September of this year, claiming that customers were misled to believe that a hair straightener did not contain specific harsh chemicals. L’Oréal is a huge company with many sub-companies. Probably everyone reading this post has at least one L’Oréal product in their personal care collection. I don’t know if the company did or did not intentionally mislead - but the subject of L’Oréal's lawsuit provides a good opportunity to talk about the strong chemicals used in products that change our hair.

What chemicals are used in hair straighteners?

Hair straighteners are usually made from lye. Lye is a strong corrosive chemical called sodium hydroxide, and it is dangerous. It is also used in products like Drano to unclog your drain.  If splashed into your eyes it can burn them blind.

Back when I was in medical school we had to learn about the horrors of what happens when curious children find Drano under the kitchen sink and unwittingly drink it...I have a visceral fear of sodium hydroxide from that lecture series, and was sure to never keep Drano in the house when my kids were little.

Lye also straightens hair.

How does lye straighten hair?

It does this by breaking chemical bonds in the hair itself to release the tight curling of the hair shaft. This chemical can chemically burn skin because it is a corrosive base. It is important to understand that - just like strong acids - chemicals that are strong bases are potentially corrosive and can burn skin. L’Oréal’s Softsheen Carson Optimum Salon Haircare Amla Legend No-Mix No-Lye Relaxer contains lithium hydroxide, which is technically not sodium hydroxide - but it is a ‘cousin’.

Lithium hydroxide is a chemical that is a strong and caustic base.

When I search for the ingredients on this product I find different lists. Softsheen-Carson appears to be a L’Oreal company, and the most reliable source lists the following ingredients:


Lithium hydroxide is an alkali and caustic base much like sodium hydroxide. Hair straighteners that use this family of chemicals are caustic and can burn skin. So, while sodium hydroxide and lithium hydroxide are not the same, the fact remains that both are caustic chemicals designed to break the chemical bonds in hair, and thus both are caustic to the skin. Be aware that there is another chemical called calcium hydroxide which is in the same family of caustic bases.

How can hair straighteners cause hair loss?

There are two main ways that this can happen.
  1. Hair straighteners can cause a chemical burn to the skin, resulting in temporary or permanent damage to the hair follicles.
  2. Straighteners can also cause temporary hair loss by creating brittle shafts that break easily.

A chemical burn is a skin burn due to exposure of the skin to a chemical that destroys skin cells and structures. When skin is significantly chemically burned, hair follicles can also be destroyed. This results in permanent hair loss of the burned area.

Hair loss also occurs with chemical hair straighteners due to brittleness and mechanical fragility after straightening. Straighteners work by breaking chemical bonds within the hair structure. Understandably, this weakens hair - making it more prone to breakage.

Using a stronger application process for hair straightener will make the hair shaft more fragile, which will speed up breakage. Also, exposing a given portion of a hair shaft to straightening chemicals more than once will compound this risk of shaft fragility. The good news is that if follicles were not damaged, hair will regrow!

Hair shafts are renewable, so if the hair follicle remains present and intact then new and strong hair will slowly replace the brittle and breakable treated hair as the shaft grows out.

Scalp hair grows an average of 1cm per month. On the other hand, skin that burned to the point where hair follicles were damaged or destroyed will not recover so easily. In fact, improper use of the more common sodium hydroxide straighteners has been long known in dermatology to cause “devastating damage to the scalp and hair.” (Fisher’s Contact Dermatitis, Fourth Edition, Robert L. Reitschel, Joseph F. Fowler, Jr.  Williams & Wilkins, 1995, pg 73)

Permanent wave solutions (to create curly hair) are also caustic - as are many other hair-altering products.

Proceed with caution when using harsh hair care products! The use of strong and potentially irritating hair care products is always risky. According to Fisher’s Contact Dermatitis, the scalp is surprisingly resistant to injury relative to the adjacent facial, neck, and behind-the-ears skin.  However, it is not indestructible. And, scalp damage can result in permanent hair loss. Understand that healthy skin depends on its ability to resist penetration of substances.  This means that the structural integrity of both the dead and living cellular layers needs to resist penetration. Any injury or rash indicates a break in this barrier - and thus heightened risk of further injury. This includes dandruff, a common skin disorder.

What are some precautions to take when using harsh hair products?

  • Always protect adjacent skin according to the manufacturers instructions.
  • When using a hair relaxer, permanent wave product, or hair coloring agent, any stinging sensation is an indication that the product is penetrating the skin and beginning to cause caustic irritation that may potentially result in a chemical burn.
  • Damaged skin, or skin with a rash should never be treated.
  • Expertise in application is also important – these are strong chemicals.
  • Adding a second application of caustic chemicals after straightening, including dyes, will potentially further irritate skin - much like putting lemon juice on a cut. This could compound the injury. The same concern with skin irritation holds true for other caustic hair products, including peroxide dyes and permanent wave solutions (such as those made from thioglycolate).
  • Hair care products are strong and potentially dangerous - which is why hair care professionals must be licensed. Even still, I want everyone to be informed on this subject, so that you can let your hair care professional know if you experience stinging or irritation. Let them know, and make sure they are responsive so you don't suffer serious damage!

Traction alopecia as a cause of hair loss. 

It is important to know that exposing your scalp to harsh haircare products is not the only cause of traumatic hair follicle injury. Pulling tightly on hair shafts such as when wearing wigs or pulling hair into cornrows, dreadlocks, buns and ponytails can damage hair follicles and lead to a permanent hair loss called traction alopecia. 

The bottom line from a dermatologist regarding harsh haircare products and styling:

Our natural hair is resistant to change and we often resort to harsh chemicals and styling practices to change its appearance. Our tough hair and resilient hair follicles are not indestructible; be really careful when using harsh styling products or practices because they can cause permanent hair loss.  

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