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Sulfate vs Sulfate Free Shampoo: Is One Better Than The Other?

August 3, 2022

 by

Verna Meachum

Learn about whether sulfate vs sulfate free shampoo is better for your hair or not

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With extensive experience in the beauty industry, I specialize in writing for curly hair care brands, websites, and magazines.

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Last Updated on April 9, 2023 by Verna Meachum

How do you know if a shampoo is sulfate free? How can you tell the difference between sulfate vs sulfate free shampoo? And what exactly are sulfates anyway? These are all valid questions, and ones that we’re here to answer.

Sulfates are detergents that are used in a variety of cleansing products, including shampoos. They help to produce a foamy lather that can remove dirt, oil, and other debris from hair.

However, some people find that sulfates can be harsh on their scalp, causing irritation and dryness. Sulfate free shampoos are designed to be gentler on the scalp, and they often contain moisturizing ingredients that can help to keep hair healthy and hydrated.

So, how can you tell if a shampoo is sulfate free? The best way is to check the ingredient list. If you see “sodium lauryl sulfate” or “sodium laureth sulfate,” then the shampoo contains sulfates. If you don’t see those ingredients listed, then the shampoo is probably sulfate free.

Shampoo Formulation

A shampoo formulation aims to clean hair fibers and remove oils or greasiness from the hair shaft and scalp surface. It also targets to get rid of product residue, build up materials, and dirt particles.

Over the years, formulators have developed 2-n-1 conditioning shampoos that can be used to clean and condition simultaneously. It cleans your hair while also conditioning it to make it easier to comb, manage, and style.

Surfactants

Sulfate vs sulfate free shampoo - foam

The main component of a shampoo formulation is the surfactant system which is the key ingredient responsible for cleansing and foaming features.

Surfactants are chemical compounds responsible to clean the surface, remove oils and greasiness as well as the undesired dirt particles.  

Traditionally, hair shampoos contain sodium lauryl sulfate (SLS) and Sodium Laureth Sulfate (SLES) as the main surfactant and cleansing agents.1 Both belong to the family of “sulfates”.

Recently, “sulfate-free” products have been gaining popularity in the market, claiming to be better, more gentle, and milder to the skin and hair fibers than sulfates.

Product formulators have come up with different strategies to formulate sulfate-free hair shampoos.

All sulfate-free products having different compositions claim to be mild and gentle. However, this may not be true, and the product may not be suitable for skin friendly as one would expect.

The fundamental question is – Is sulfate-free truly gentle and mild to scalp skin and hair fibers? Or is it just a marketing gimmick?

Let’s take a deeper look at the chemical makeup of sulfates and sulfate-free formulations. More importantly, what factors should we keep an eye on when selecting a suitable and mild sulfate-free solution?

Sulfate vs Sulfate-Free Shampoo

Sodium lauryl sulfate (SLS) or its sister compound, sodium Laureth sulfate (SLES) is a common ingredient in most market shampoos.

Other sulfates include, ammonium lauryl sulfate and ammonium Laureth sulfate, which are also commonly used in hair cleansing formulations.

SLS is a commonly used surfactant in personal care formulations, toothpaste products, and other household detergents.

Sulfates have been criticized in recent hair care studies as well as the curly hair community for being harsh and having a negative effect on hair and scalp quality.

Scientific reports have reported such details and have highlighted protein loss on repeated washing with sulfates.2-4

Formulators responded to market and consumer anxiety by developing an alternative approach known as “Sulfate-Free.” Various scientific reports have reported their positive impact on hair quality.

However, does switching from sulfate to sulfate-free make it any better for hair? In a nutshell, the answer is no. Sulfate-free formulas are not all created equal, and surprise, some may not be gentle.

A formulation is similar to a winning soccer team where each ingredient is a vital player. Each ingredient must perform and deliver the desired positive results.

Even a sulfate-free formulation may contain an ingredient that has a harsh or negative effect on your hair and scalp.

In terms of a shampoo (for example), whether it is sulfate or sulfate-free, its complete ingredient listing should be thoroughly examined before applying it to the hair.

Any single ingredient you may have a problem with in the mix should be avoided.

Note: These shampoo sulfates must not be confused with inorganic salts e.g. sodium sulfate, calcium sulfate, etc. They are completely different molecules with different chemistry.

Chemistry of Sulfate Free Shampoo

A typical sulfate-free shampoo contains a blend of mild surfactants. Generally, such formulation comprises 2-3 surfactants which are carefully selected and blended to generate a good volume of creamy lather.

A list of sulfate-alternative surfactants, which are the most common ingredients in sulfate-free shampoos, is provided below.

Among them, glucose-derived Coco glucoside, Decyl glucoside, and Lauryl glucoside are top-rated surfactants due to their green origin, superb mildness, sustainability, and biodegradation.

Sodium lauryl glutamate and amino acid derivatives are also popular. They are known for their excellent mildness as well as decreasing the overall irritation potential of the whole formulation.

The formulation may also contain conditioning ingredients such as Guar Hydroxypropyltrimonium Chloride or polyquaternium-10, which are two excellent choices in detangling hair fibers, improving wet and dry combing, and delivering long last conditioning.

Other ingredients the formulation may comprise are foam booster (e.g. coco betaine), viscosity controlling agent (cocamide DEA, Cocamide MEA, DEO-120 Glutamate, Glycerin, Propylene Glycol or butylene glycol), silicones, herbal extracts, proteins, perfumes, and preservatives.

Note: Consumers should be aware of some of these ingredients, as their presence might not be positive or beneficial.

Examples of Sulfate Free Surfactants (Key Ingredient)

Non-Ionic Surfactants, compounds with no charge density

·      Glucosides (Coco Glucoside, Decyl Glucoside, Lauryl Glucoside)

Anionic Surfactants, compounds carrying negative charges

·      Sodium Cocoyl Isethionate

·      Sodium Lauroyl Methyl Isethionate

·      Diethylhexyl Sodium Sulfosuccinate

·      Sodium Laureth Sulfosuccinate

·      Sodium C14-16 Olefin Sulfonate

·      Sodium Lauroyl Sarcosinate

Amino acid-derived weakly anionics

·      Sodium Cocoyl Glutamate

·      Disodium Cocoyl Glutamate

·      Sodium Myristoyl Glutamate

·      Sodium Lauroyl Glutamate

Amphoteric, compounds carrying both positive and negative charges

·      Coco-Betaine

·      Cocamidopropyl Betaine

·      Sodium Lauroamphoacetate

·      Sodium Cocoamphoacetate

·      Sodium Sodium Cocoamphopropionate

·      Disodium Cocoamphodiacetate

What To Look For In A Sulfate Free Shampoo?

Sulfate vs sulfate free shampoo - ingredients

The most important feature to look for in a sulfate free shampoo is its complete ingredient listing. Examine the product’s ingredient list to see if it is compatible with your hair and scalp.

Here are some INCI-related facts:

Go for Green surfactants

A shampoo normally contains 2-3 surfactants blended as mentioned above. The first one listed is called “Primary Surfactant” while 2nd and 3rd are called “Co-Surfactants”. Primary surfactant is the backbone of the formulation.

It is strongly recommended to go for a nature-derived, plant-sourced biodegradable surfactant. They are gentle and mild on skin and hair and they have the least negative impact on our environment.

From the above list, Glucosides are the favorite. They are sugar derived with excellent mildness and skin compatibility. Next in line are amino acid-derived glutamates. They are also known for their skin moisturization and mildness.

Avoid Amides

Examples are Cocamide DEA, Lauramide DEA, etc. They are viscosity modifiers and also stabilize foam. However, they may contain free amines which may go on to react and form nitrosamines. These derivatives are susceptible to carcinogenic.

Some manufacturers still use them due to their cost effectiveness and high viscosity response. Consumers are strongly encouraged to avoid formulations containing these amides.

Preservatives, Formaldehyde Donors

Formaldehyde (also known as formal or formal) is carcinogenic and is not currently used for personal care products.

However, certain preservatives are formaldehyde donors and are still frequently added even into sulfate-free formulations.

These preservative molecules release formaldehyde over time. Examples are, DMDM-Hydantoin, Imidazolidinyl Urea, Diazolidinyl Urea.5

Similarly, parabens are suspected cancer-causing agents and should be avoided.

Takeaway

Please remember that having a sulfate-free shampoo does not necessarily mean it is safe, gentle, and mild to your hair and scalp surface.

It is greatly important to examine the ingredient listing and make sure it does not contain any harmful ingredient.

A formulation is a winning combination of ingredients. A single sulfate-free alternate does not mean it is completely safe and may not cause any harsh impact on scalp and hair fibers. This is more important for fine, curly hairs and consumers with sensitive scalp.

Always be vigilant!!



Last Updated on September 5, 2022 by Verna Meachum

How do you know if a shampoo is sulfate free? How can you tell the difference between sulfate vs sulfate free shampoo? And what exactly are sulfates anyway? These are all valid questions, and ones that we’re here to answer.

Sulfates are detergents that are used in a variety of cleansing products, including shampoos. They help to produce a foamy lather that can remove dirt, oil, and other debris from hair.

However, some people find that sulfates can be harsh on their scalp, causing irritation and dryness. Sulfate free shampoos are designed to be gentler on the scalp, and they often contain moisturizing ingredients that can help to keep hair healthy and hydrated.

So, how can you tell if a shampoo is sulfate free? The best way is to check the ingredient list. If you see “sodium lauryl sulfate” or “sodium laureth sulfate,” then the shampoo contains sulfates. If you don’t see those ingredients listed, then the shampoo is probably sulfate free.

Shampoo Formulation

shampoo formulation aims to clean hair fibers and remove oils or greasiness from the hair shaft and scalp surface. It also targets to get rid of product residue, build up materials, and dirt particles.

Over the years, formulators have developed 2-n-1 conditioning shampoos that can be used to clean and condition simultaneously. It cleans your hair while also conditioning it to make it easier to comb, manage, and style.

SURFACTANTS

Sulfate vs sulfate free shampoo - foam

The main component of a shampoo formulation is the surfactant system which is the key ingredient responsible for cleansing and foaming features.

Surfactants are chemical compounds responsible to clean the surface, remove oils and greasiness as well as the undesired dirt particles.  

Traditionally, hair shampoos contain sodium lauryl sulfate (SLS) and Sodium Laureth Sulfate (SLES) as the main surfactant and cleansing agents.1 Both belong to the family of “sulfates”.

Recently, “sulfate-free” products have been gaining popularity in the market, claiming to be better, more gentle, and milder to the skin and hair fibers than sulfates.

Product formulators have come up with different strategies to formulate sulfate-free hair shampoos.

All sulfate-free products having different compositions claim to be mild and gentle. However, this may not be true, and the product may not be suitable for skin friendly as one would expect.

The fundamental question is – Is sulfate-free truly gentle and mild to scalp skin and hair fibers? Or is it just a marketing gimmick?

Let’s take a deeper look at the chemical makeup of sulfates and sulfate-free formulations. More importantly, what factors should we keep an eye on when selecting a suitable and mild sulfate-free solution?

Sulfate vs Sulfate-Free Shampoo

Sodium lauryl sulfate (SLS) or its sister compound, sodium Laureth sulfate (SLES) is a common ingredient in most market shampoos.

Other sulfates include, ammonium lauryl sulfate and ammonium Laureth sulfate, which are also commonly used in hair cleansing formulations.

SLS is a commonly used surfactant in personal care formulations, toothpaste products, and other household detergents.

Sulfates have been criticized in recent hair care studies as well as the curly hair community for being harsh and having a negative effect on hair and scalp quality.

Scientific reports have reported such details and have highlighted protein loss on repeated washing with sulfates.2-4

Formulators responded to market and consumer anxiety by developing an alternative approach known as “Sulfate-Free.” Various scientific reports have reported their positive impact on hair quality.

However, does switching from sulfate to sulfate-free make it any better for hair? In a nutshell, the answer is no. Sulfate-free formulas are not all created equal, and surprise, some may not be gentle.

A formulation is similar to a winning soccer team where each ingredient is a vital player. Each ingredient must perform and deliver the desired positive results.

Even a sulfate-free formulation may contain an ingredient that has a harsh or negative effect on your hair and scalp.

In terms of a shampoo (for example), whether it is sulfate or sulfate-free, its complete ingredient listing should be thoroughly examined before applying it to the hair.

Any single ingredient you may have a problem with in the mix should be avoided.

Note: These shampoo sulfates must not be confused with inorganic salts e.g. sodium sulfate, calcium sulfate, etc. They are completely different molecules with different chemistry.

Chemistry of Sulfate Free Shampoo

A typical sulfate-free shampoo contains a blend of mild surfactants. Generally, such formulation comprises 2-3 surfactants which are carefully selected and blended to generate a good volume of creamy lather.

A list of sulfate-alternative surfactants, which are the most common ingredients in sulfate-free shampoos, is provided below.

Among them, glucose-derived Coco glucoside, Decyl glucoside, and Lauryl glucoside are top-rated surfactants due to their green origin, superb mildness, sustainability, and biodegradation.

Sodium lauryl glutamate and amino acid derivatives are also popular. They are known for their excellent mildness as well as decreasing the overall irritation potential of the whole formulation.

The formulation may also contain conditioning ingredients such as Guar Hydroxypropyltrimonium Chloride or polyquaternium-10, which are two excellent choices in detangling hair fibers, improving wet and dry combing, and delivering long last conditioning.

Other ingredients the formulation may comprise are foam booster (e.g. coco betaine), viscosity controlling agent (cocamide DEA, Cocamide MEA, DEO-120 Glutamate, Glycerin, Propylene Glycol or butylene glycol), silicones, herbal extracts, proteins, perfumes, and preservatives.

Note: Consumers should be aware of some of these ingredients, as their presence might not be positive or beneficial.

EXAMPLES OF SULFATE FREE SURFACTANTS (KEY INGREDIENT)

Non-Ionic Surfactants, compounds with no charge density

·      Glucosides (Coco Glucoside, Decyl Glucoside, Lauryl Glucoside)

Anionic Surfactants, compounds carrying negative charges

·      Sodium Cocoyl Isethionate

·      Sodium Lauroyl Methyl Isethionate

·      Diethylhexyl Sodium Sulfosuccinate

·      Sodium Laureth Sulfosuccinate

·      Sodium C14-16 Olefin Sulfonate

·      Sodium Lauroyl Sarcosinate

Amino acid-derived weakly anionics

·      Sodium Cocoyl Glutamate

·      Disodium Cocoyl Glutamate

·      Sodium Myristoyl Glutamate

·      Sodium Lauroyl Glutamate

Amphoteric, compounds carrying both positive and negative charges

·      Coco-Betaine

·      Cocamidopropyl Betaine

·      Sodium Lauroamphoacetate

·      Sodium Cocoamphoacetate

·      Sodium Sodium Cocoamphopropionate

·      Disodium Cocoamphodiacetate

What To Look For In A Sulfate Free Shampoo?

Sulfate vs sulfate free shampoo - ingredients

The most important feature to look for in a sulfate free shampoo is its complete ingredient listing. Examine the product’s ingredient list to see if it is compatible with your hair and scalp.

Here are some INCI-related facts:

GO FOR GREEN SURFACTANTS

A shampoo normally contains 2-3 surfactants blended as mentioned above. The first one listed is called “Primary Surfactant” while 2nd and 3rd are called “Co-Surfactants”. Primary surfactant is the backbone of the formulation.

It is strongly recommended to go for a nature-derived, plant-sourced biodegradable surfactant. They are gentle and mild on skin and hair and they have the least negative impact on our environment.

From the above list, Glucosides are the favorite. They are sugar derived with excellent mildness and skin compatibility. Next in line are amino acid-derived glutamates. They are also known for their skin moisturization and mildness.

AVOID AMIDES

Examples are Cocamide DEA, Lauramide DEA, etc. They are viscosity modifiers and also stabilize foam. However, they may contain free amines which may go on to react and form nitrosamines. These derivatives are susceptible to carcinogenic.

Some manufacturers still use them due to their cost effectiveness and high viscosity response. Consumers are strongly encouraged to avoid formulations containing these amides.

PRESERVATIVES, FORMALDEHYDE DONORS

Formaldehyde (also known as formal or formal) is carcinogenic and is not currently used for personal care products.

However, certain preservatives are formaldehyde donors and are still frequently added even into sulfate-free formulations.

These preservative molecules release formaldehyde over time. Examples are, DMDM-Hydantoin, Imidazolidinyl Urea, Diazolidinyl Urea.5

Similarly, parabens are suspected cancer-causing agents and should be avoided.

Takeaway

Please remember that having a sulfate-free shampoo does not necessarily mean it is safe, gentle, and mild to your hair and scalp surface.

It is greatly important to examine the ingredient listing and make sure it does not contain any harmful ingredient.

A formulation is a winning combination of ingredients. A single sulfate-free alternate does not mean it is completely safe and may not cause any harsh impact on scalp and hair fibers. This is more important for fine, curly hairs and consumers with sensitive scalp.

Always be vigilant!


References

1.  Zviak, C., The Science of Hair Care. Taylor & Francis: 1986.
2.  Wagner, R. D. C.; Joekes, I., Hair protein removal by sodium dodecyl sulfate. Colloid Surf. B-Biointerfaces 2005, 41 (1), 7-14.
3.  Trüeb, R. M., Shampoos: Ingredients, efficacy and adverse effects. JDDG: Journal der Deutschen Dermatologischen Gesellschaft 2007, 5 (5), 356-365.
4.  Turkoglu, M.; Pekmezci, E.; Sakr, A., Evaluation of irritation potential of surfactant mixtures. Inter. J. of Cosmet. Sci 1999, 21 (6), 371-382.
5.  Steinberg, D. C., Preservatives for Cosmetics. Allured Publishing Corporation: 1996.

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