Jina's Blog

Sulfates - Unraveling the Science Behind Surfactants: A Guide to Understanding Shampoo Ingredients

by James McHugo on May 01, 2023

Michel LeJeune solid shampoo



When it comes to choosing the right shampoo, a common concern among consumers is the presence of sulfates and their potential for causing irritation. Many manufacturers claim that their products are "sulfate-free," but this term can be misleading as some products may still contain milder surfactants like sodium coco-sulfate (SCS). In this article, we will explore the differences between various surfactants, their role in cleaning products such as shampoos, and how a blended surfactant solution can offer the optimal balance between cleansing and gentleness.

The Role of Surfactants in Shampoos:

Surfactants are essential ingredients in shampoos and other cleaning products because they help remove dirt, oil, and debris from the hair and scalp. They work by reducing the surface tension between water and oils, allowing the oils to mix with water and be rinsed away. Surfactants also contribute to the foaming action of shampoos, which many consumers associate with effective cleaning.

A Comparison of Common Surfactants:

There is a wide range of surfactants used in the beauty industry, with varying levels of irritability potential. The following table provides a simplified comparison of some common surfactants based on their general properties:





Irritability Potential


Sodium Lauryl Sulfate (SLS)



Strong cleansing and foaming, smaller molecule size, can be harsh on skin and hair

Sodium Laureth Sulfate (SLES)



Milder than SLS, good cleansing and foaming, less irritating due to larger molecule size and ethoxylation

Sodium Coco-Sulfate (SCS)



Derived from coconut oil, milder than SLS and SLES, good cleansing and foaming properties

Sodium Cocoyl Isethionate (SCI)



Gentle cleansing and skin conditioning, derived from coconut oil, less foaming than sulfates

Coco-Glucoside (CG)



Mild, derived from coconut oil and sugar, biodegradable, suitable for sensitive skin

Decyl Glucoside (DG)



Gentle, derived from plant-based sources like corn and coconut, biodegradable, suitable for sensitive skin

75% SCI and 25% SCS Blend


Low to Moderate

Combination of gentle cleansing (SCI) and enhanced foaming (SCS), potentially milder than pure SCS


Please note that individual skin sensitivities vary, and the irritability potential of a surfactant can also depend on factors such as concentration, formulation, and other ingredients in a product. This table is intended as a general overview and starting point for understanding the relative irritability potential of these common surfactants and the blend.

Variations in Ingredients and Manufacturing Processes for Surfactants:

The production of surfactants, including sulfates and non-sulfates, often involves different raw materials and manufacturing processes. For example, sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) are typically derived from petroleum or plant-based sources like palm oil or coconut oil. The production of SLES involves an additional step called ethoxylation, which increases the molecule size and makes it milder compared to SLS.

Sodium coco-sulfate (SCS) is produced using fatty acids from coconut oil, making it more eco-friendly than petroleum-based surfactants. The manufacturing process of SCS is somewhat similar to that of SLS, but it retains a more significant proportion of fatty acids, leading to a milder surfactant.

In contrast, sodium cocoyl isethionate (SCI) is made from coconut oil and isethionic acid. Its production results in a gentle, skin-conditioning surfactant with a different chemical structure than sulfates. Non-ionic surfactants like coco-glucoside and decyl glucoside are produced by reacting plant-based fatty alcohols (e.g., from coconut oil) with glucose or other sugars, yielding mild and biodegradable surfactants suitable for sensitive skin.

These variations in raw materials and manufacturing processes contribute to the differences in properties and irritability potential of surfactants, allowing consumers to choose products that best suit their needs and preferences.

The Molecular Structure and Its Significance:

One of the critical factors determining the irritability potential of a surfactant is its molecular structure and size. Smaller molecules can penetrate the skin more easily, which may lead to irritation. For example, sodium lauryl sulfate (SLS) has a smaller molecule size and higher irritability potential compared to sodium laureth sulfate (SLES) and sodium coco-sulfate (SCS).

Non-sulfate surfactants, such as sodium cocoyl isethionate (SCI) or decyl glucoside, have entirely different chemical structures, making them less irritating to the skin. However, these non-sulfate surfactants may not foam and clean as effectively as their sulfate counterparts.

Finding the Optimal Solution: A Blended Surfactant:

To achieve a balance between effective cleansing and reduced irritability potential, a blend of surfactants can be used. For example, a combination of 75% SCI and 25% SCS offers the benefits of gentle cleansing from SCI and enhanced foaming and cleaning properties from SCS. This blend is potentially milder than pure SCS and can be an ideal option for those seeking a quality shampoo with reduced irritability potential.

The Misleading "Sulfate-Free" Claim:

It is essential for consumers to be aware that the term "sulfate-free" can be misleading when it comes to shampoo labeling. Some manufacturers may claim their product is sulfate-free while still containing milder surfactants like SCS. Although SCS is considered less irritating than SLS or SLES, it is still a sulfate-based surfactant. Consumers should carefully read ingredient lists to ensure they understand the specific surfactants used in a product.


Understanding the role of surfactants in shampoos and their differences is crucial for making informed decisions when choosing hair care products. By being aware of the potential misleading nature of "sulfate-free" claims, consumers can make better choices for their hair care needs.  A blended surfactant solution, such as a combination of 75% SCI and 25% SCS, may offer an optimal balance between effective cleaning and gentleness.

Introducing Michel LeJeune Professional Solid Shampoos.

Following on from this discussion on sulfates, we have identified a solid shampoo that fits the bill:  Michel LeJeune POS – which stands for Professional Organic System – range of solid shampoos. 

Michel LeJeune Professional solid shampoo

Michel LeJeune is a hairdresser, formerly to the stars, now to his own clientele located in the South of France.  He developed the world’s first professional solid shampoo.  He did so not because of its eco-benefits, but because he was struggling with travelling with his stars all over the world and carrying large bottles of shampoo, especially to the Middle-East with its deserts and strict import restrictions. This solid shampoo is used in exclusively in his salon, as well as 50 and growing other salons in the region.

Having used this product exclusively on my hair for the past year and a half, I can tell you it is an amazing shampoo.  My hair is full of luster and bounce, and best of all I find I can wash my hair much less frequently, with it staying clean and fresh much longer in between washes.

Michel LeJeune's solid shampoos can be found here.  Warning: it does not come cheap – but that reflects its qualities, the fact that it is handmade in France, with expensive professional ingredients that you will not find in other shampoos, and that one 80 gram bar of soap can manage between 60 – 80 washes, the same as an equivalent of 2 or 4 250ml bottles of shampoo.  This may sound extreme, but it is not when you consider the density of the shampoo, which is pressed as part of the manufacturing process, and the fact that most of that shampoo that you are using consists of nothing other than water.

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