Sodium Laureth Sulfate in cosmetics, how harmful it is?

Main reason to start using natural cosmetics is the chemicals in traditional industrial cosmetic products. The possible health effects of cosmetic chemicals are often criticized and feared. They can be potentially very toxic. However, many chemicals do not pose a direct risk to health. However, they can be extremely harmful to the skin and the environment. One very common ingredient in cosmetic products is Sodium Laureth Sulfate, SLS.


What is Sodium Lauryl Sulfate?

SLS or Sodium Lauryl Sulfate or Sodium Laureth Sulfate is a very versatile chemical. It is produced using either mineral oil or vegetable oils such as coconut oil or palm oil. SLS is chemically processed from lauryl alcohol and sulfuric acid. Then the chemical is neutralized with sodium carbonate aka washing soda.

SLS is a surfactant which are very versatile chemicals. They remove tension from the surface of the water.  When the surface tension is removed, the water can penetrate deeper and wider. The surfactants are extremely detergent, meaning they remove grease and other dirt effectively.

SLS has amphiphilic properties

This means that SLS acts as an emulsifier. Water and oil form a cream when adding SLS to the mixture.

SLS is very foamy. It forms a thick, durable foam in all products to which it has been added.

SLS is one of the most common chemicals in cosmetics

Due to its versatile features, SLS is very popular. It is found in all cosmetic products, from shampoos and shower soaps to moisturizers and cleansing milks. You will also find SLS in regular toothpastes.

It is very difficult to come up with a product that SLS would not fit. Cosmetics industry simply needs this substance with so many required properties.

How SLS affects skin and hair?

SLS is a well-tolerated ingredient

SLS is suitable for the skin because it causes little to no allergies or hypersensitivity. If you are sensitized to any cosmetic ingredient it is probably not SLS but some other ingredient. The cosmetics industry has decades of experience in the suitability of SLS for skin care. It has been found to be safe in principle and is therefore used as the very first option when adding detergents to the product.

Persons who are intolerant to plant-based products may well tolerate SLS. SLS has also not been identified as a carcinogenic chemical.

Although SLS does not actually cause sensitization, it does not mean it a safe ingredient for the skin.

So why is SLS not a good ingredient in cosmetics?

SLS is a powerful dehydrator

SLS is also a highly detergent ingredient. Therefore, it dries the skin, sculp and hair. SLS is the only ingredient in shampoos that makes your hair “crunchy”. It is very difficult to achieve a similar washing result with any other cosmetic ingredient.  We are used to use strong washing shampoos and detergents throughout our lives so we are also used to get the “crunchy” result.


SLS is best tolerated in shower soaps, gels and shampoos because it is rinsed off quickly. This will reduce the skin irritation.

Household Cleaners and Laundry Detergents

SLS is also commonly used in household cleaners and laundry detergents. It is worth considering whether the same chemical is suitable for washing skin, hair, teeth, floor and laundry – and car.

In shower soaps and gels, the unnecessarily strong washing effect of SLS is diluted by adding oils to the product. The cosmetics industry talks about curative shower products. My question is why SLS is used at all if it causes skin problems.

SLS as an emulsifier for creams

SLS is one of the most stable and effective emulsifiers. It is also very affordable. When purchasing home cosmetics emulsifiers, avoid emulsifying wax. All emulsifying waxes are made from SLS. The emulsifying wax is a very drying ingredient. It should not be used at all, especially in products that are mentioned to stay on the skin. Many manufacturers are adding emulsifying wax to shampoo and shower soaps/gels. There are much better emulsifiers for this purpose.

SLS causes skin and eye irritation

The irritation caused by SLS is caused precisely by its detergent property. All of the skin’s own protective fat and sebum are very effectively washed away. This will make the skin more exposed to many external stimulations. Removing the fat and sebum cause itching and irritation. Symptoms are similar to allergies and hypersensitivity but they are caused by SLS.

Skin rash and eczma

SLS also aggravates previous skin symptoms. Continuous washing of dry skin suffering rash using strongly detergent products may aggravate symptoms.

SLS in toothpastes


SLS is widely used in toothpastes. Consumers obviously want the toothpaste to foam. People do not believe that paste cleans without foam – or do they?  The foaming property of SLS is very commonly used in toothpastes. There are very few non-foaming toothpastes available. It is very difficult to find a toothpaste without SLS in a regular shop.

Mouth Odours

SLS has also been found to affect mouth odours. It neutralizes odours to some extent. Therefore, it is a highly desirable chemical in dental care.

SLS also does its damage in the mouth.

It has been found to cause aphtha, or small painful blisters on the oral mucosa. Patients suffering aphthous ulcers have switched to a more natural version of toothpaste and have got rid of them.

Cracked Lips

Toothpaste containing SLS is in many cases the reason for mouth sores and fractured, cracked lips. You should try changing toothpaste if you suffer from such symptoms.

SLS is also claimed to reduce the effect of fluoride on toothpastes. Here’s another reason to avoid SLS in toothpastes.

SLS and palm oil

SLS contains lauryl acid, which is a natural ingredient in coconut fat. Sometimes, SLS is called sodium coco sulphate, emphasizing that lauryl acid is coming from coconut. However, the chemical is completely the same and just as harmful to skin and hair as SLS.

Make Sure You Know the Origin of Lauryl Acid

Lauryl acid of Sodium Laureth Sulfate is often made from mineral oil or coconut but also from palm oil. If you want to avoid the use of palm oil for ethical reasons, make sure you know the origin of lauryl acid. It may be, however, an impossible task. The products of chemical industry are sold all over the globe. It is not always possible to identify an individual product, even in case when the producer is a responsible company.

How to find SLS in cosmetics?


You should learn to recognize all different names of SLS and its aliases that appear on products by using INCI-lists. The cosmetics industry would not give up a good, versatile and inexpensive raw material. Therefore, SLS has over 100 different chemical and commercial names. It is therefore quite impossible for an average consumer to learn all the possible names of the same chemical.

Here are Some Common Names of SLS

However, here are some common names. The most common trick is to replace word lauryl with coco in SLS. This gives an idea of ​​the natural ingredient. We know this is not true. SLS is always a synthetic chemical that cannot be found in nature.

Different names of SLS

  • Sulfuric acid monododecyl Ester sodium salt
  • Sodium salt hydrogen sulphate
  • Dodecyl alcohol
  • Sodium dodecane sulfonate
  • Sodium monododecyl sulphate
  • Sodium Coco sulphate
Similar substances that you should also avoid
  • Ammonium lauryl sulphate (ALS) ammonium dodecyl sulphate
  • Potassium lauryl sulphate

How to replace products containing SLS?


The easiest way to replace products containing SLS is to use soap-based products. Marseille soap contains only natural ingredients and is great for the skin.

There are currently many sulphate-free alternatives for hair washing. Your local store selling only natural cosmetics would be glad to guide you. They are presumably the experts.

Curly Girl

Natural, eco-friendly Curly Girl method is very recommendable way to treat hair. Curly Girl products are suitable for both curly and straight hair as they are much gentler and contain no silicones or sulphates.

Consider changing your toothpaste to more natural product. Be careful because many toothpastes considered eco-friendly and naturals contain some form of SLS. People do not buy paste that without foam. Or do they?  Here’s how to make homemade toothpaste.

Make Your Own, Natural Hair Wash

If you want to make your own, natural hair wash, try aloe vera juice of which I have written here. Aloe Vera contains saponins, which are natural cleansing agents. They do not wash the skin too clean and do not remove the skin’s own protective layer of sebum.

Are you trying to avoid products containing SLS?

Leave a Reply

Your email address will not be published. Required fields are marked *


Active ingredients in homemade cosmetic cream

Read post