Sodium Lauryl Sulfate (SLS)

SOH-dee-um LOR-ul SUL-fate

INCI: Sodium Lauryl Sulfate

Surfactant 4/10 Safety Not CGAvoid Semi-synthetic Vegan

What Is Sodium Lauryl Sulfate (SLS)?

Sodium Lauryl Sulfate is an anionic surfactant derived from coconut or palm kernel oil. It is one of the most effective cleansing agents used in shampoos and produces a rich lather. SLS strips oil and buildup from hair and scalp very efficiently, but can be overly harsh for many hair types.

Source: Coconut oil or palm kernel oil (chemically processed)

Origin: Semi-synthetic

Also known as: SLS, Sodium Dodecyl Sulfate, Lauryl Sodium Sulfate

What Does Sodium Lauryl Sulfate (SLS) Do to Your Hair?

SLS works by reducing the surface tension of water, allowing it to mix with oils and dirt on the hair and scalp. It creates a strong lather that removes sebum, product buildup, and environmental pollutants. It is considered one of the strongest surfactants used in consumer hair care.

Best For

Oily hair, heavy buildup, clarifying needs

Not Recommended For

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

Concentration Matters

5-25%

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
Color-treated: Use caution

Method Compatibility

Curly Girl (CG) Method: Avoid
CG Avoid

Safety & Regulation

4/10
AvoidCautionSafe

Can cause scalp irritation, dryness, and strip natural oils. May exacerbate eczema and dermatitis. Linked to eye irritation at high concentrations.

FDA Status: Generally Recognized As Safe

FDA permits use in cosmetics with no specific concentration limits. CIR panel reviewed and found safe in rinse-off products.

EWG Score: 2/10

HairAide Verdict

SLS is a powerful cleanser best reserved for occasional clarifying use. It is too harsh for daily use on most hair types, especially curly, dry, or color-treated hair. If you need a deep clean, use an SLS shampoo once a month at most and follow with a deep conditioner.

Products That Contain Sodium Lauryl Sulfate (SLS)

Shampoos, clarifying shampoos, body washes

Alternatives to Sodium Lauryl Sulfate (SLS)

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

Sodium Cocoyl Isethionate, Cocamidopropyl Betaine, Decyl Glucoside

Frequently Asked Questions

Is Sodium Lauryl Sulfate (SLS) safe for hair?

Sodium Lauryl Sulfate (SLS) has a safety rating of 4/10. It's generally acceptable but may cause issues for some hair types. Can cause scalp irritation, dryness, and strip natural oils. May exacerbate eczema and dermatitis. Linked to eye irritation at high concentrations.

Is Sodium Lauryl Sulfate (SLS) bad for curly hair?

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

Is Sodium Lauryl Sulfate (SLS) CG-method approved?

No, Sodium Lauryl Sulfate (SLS) is not approved for the Curly Girl method.

What can I use instead of Sodium Lauryl Sulfate (SLS)?

Some alternatives to Sodium Lauryl Sulfate (SLS) include: Sodium Cocoyl Isethionate, Cocamidopropyl Betaine, Decyl Glucoside

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