Sodium Laureth Sulfate (SLES)

SOH-dee-um LOR-eth SUL-fate

INCI: Sodium Laureth Sulfate

Surfactant 5/10 Safety Not CGControversial Semi-synthetic Vegan

What Is Sodium Laureth Sulfate (SLES)?

Sodium Laureth Sulfate is a milder anionic surfactant closely related to SLS. It undergoes an additional chemical process called ethoxylation, which makes it gentler on skin and hair while still providing effective cleansing. SLES is the most widely used surfactant in mainstream shampoos worldwide.

Source: Coconut oil or palm kernel oil (ethoxylated)

Origin: Semi-synthetic

Also known as: SLES, Sodium Lauryl Ether Sulfate

What Does Sodium Laureth Sulfate (SLES) Do to Your Hair?

SLES lowers surface tension to emulsify oils and dirt, producing abundant foam. The ethoxylation process makes it significantly less irritating than SLS while retaining strong cleansing power. It effectively removes buildup without stripping hair as aggressively as its non-ethoxylated counterpart.

Best For

Normal to oily hair, regular cleansing

Not Recommended For

Curly hair (3A-4C), very dry hair, sensitive scalp

Concentration Matters

8-20%

Hair Type Compatibility

1A Straight Fine
1B Straight Medium
1C Straight Coarse
2A Wavy Fine
2B Wavy Medium
2C Wavy Coarse
3A Curly Loose
3B Curly Tight
3C Curly Corkscrew
4A Coily S-Shaped
4B Coily Z-Shaped
4C Coily Tight

Method Compatibility

Curly Girl (CG) Method: Avoid
CG Avoid

Safety & Regulation

5/10
AvoidCautionSafe

Milder than SLS but can still cause dryness with daily use. The ethoxylation process may introduce trace amounts of 1,4-dioxane, a potential contaminant. Generally well-tolerated by most people.

FDA Status: Generally Recognized As Safe

FDA permits use in cosmetics. CIR panel considers safe when formulated to be non-irritating. 1,4-dioxane contamination monitored by FDA.

EWG Score: 3/10

HairAide Verdict

SLES is a solid middle-ground surfactant that works well for most hair types when not used daily. It is gentler than SLS but still too stripping for very dry or curly hair. For normal to oily hair, an SLES shampoo used a few times per week is perfectly reasonable.

Products That Contain Sodium Laureth Sulfate (SLES)

Shampoos, clarifying shampoos, volumizing shampoos

Alternatives to Sodium Laureth Sulfate (SLES)

If you want to avoid Sodium Laureth Sulfate (SLES), look for products with these ingredients instead:

Cocamidopropyl Betaine, Sodium Cocoyl Isethionate, Coco-Glucoside

Frequently Asked Questions

Is Sodium Laureth Sulfate (SLES) safe for hair?

Sodium Laureth Sulfate (SLES) has a safety rating of 5/10. It's generally acceptable but may cause issues for some hair types. Milder than SLS but can still cause dryness with daily use. The ethoxylation process may introduce trace amounts of 1,4-dioxane, a potential contaminant. Generally well-tolerated by most people.

Is Sodium Laureth Sulfate (SLES) bad for curly hair?

Sodium Laureth Sulfate (SLES) is not CG-method approved. Curly hair types may want to avoid this ingredient or use products containing it sparingly.

Is Sodium Laureth Sulfate (SLES) CG-method approved?

No, Sodium Laureth Sulfate (SLES) is not approved for the Curly Girl method.

What can I use instead of Sodium Laureth Sulfate (SLES)?

Some alternatives to Sodium Laureth Sulfate (SLES) include: Cocamidopropyl Betaine, Sodium Cocoyl Isethionate, Coco-Glucoside

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