Disodium Laureth Sulfosuccinate

Overview

Disodium Laureth Sulfosuccinate is a mild anionic surfactant in the sulfosuccinate family. It is rarely used as the sole surfactant in a cleansing product — its job is to act as a secondary or supporting surfactant, paired with a stronger primary surfactant. In that role it provides three useful functions: it boosts the foam volume and stability, it softens the feel of harsher primary surfactants, and it adds genuine gentleness to the overall blend.

It is supplied as a clear to slightly cloudy thick liquid, typically at 30-40% active content (the rest is water), with a faint sweet odor. Fully water-soluble. Shelf life is 18-24 months stored cool.

Published evidence on its mildness is solid — sulfosuccinate-family surfactants consistently appear in the gentlest tier of dermatologically tested cleansers, and the addition of even 5-10% disodium laureth sulfosuccinate to a sulfate-based formula measurably reduces the skin-irritation profile of the overall blend.

It is a workhorse ingredient in baby washes, gentle facial cleansers, and high-end shampoos where the formulator wants to keep stronger surfactants in the blend (for cleaning power) but soften their character (for mildness).

What it does in a formula

The molecule has a relatively large, well-shielded charged head and a moderate-length fatty tail. This shape makes it less aggressive at disrupting skin lipids than smaller, more pointed surfactants. When mixed with a stronger surfactant, the larger sulfosuccinate molecules partly intersperse between the smaller, harsher molecules, effectively diluting the harshness at the skin surface during foaming.

It also has a useful foam-boosting effect — the foam from a blend containing 10% sulfosuccinate is denser and more stable than from the primary surfactant alone.

How to use

Add to the water phase or to the cool-down depending on the supplier’s recommendation. Most DIY-grade versions can be added at any temperature without degradation. Stir gently to incorporate; vigorous stirring creates excessive foam.

Usage rates by product type:

• Baby washes (very gentle): 20-25%
• Facial cleansers (mild): 10-20%
• Body washes: 10-20%
• Shampoos (mild): 10-25%
• Bubble baths: 15-25%
• Hand washes: 5-15%

The standard rate for “gentleness boost” use is around 10-15%. The high end (25%) is used in genuine mildness-positioning formulas.

Best for / Worst for

Best for: baby and very sensitive skin formulas, shampoos for color-treated hair, formulators making mild-positioning cleansers, products where the primary surfactant alone is too harsh, foam-boosting in low-foam formulations.

Worst for: anhydrous bar products (water-soluble), formulas at very low pH (below 3.5 the surfactant performance drops), super-clarifying shampoos where mildness is not the goal.

Common pitfalls

Confusing supplier-listed active percentage with the use-percentage. Most DIY suppliers sell sulfosuccinate at 30-40% active. A formula calling for “10% disodium laureth sulfosuccinate” usually means 10% of the supplier liquid, not 10% pure active. Read the supplier specification.

Vigorous stirring during incorporation. Creates excessive foam that interferes with formulation. Slow gentle stirring is better.

Using it as the only surfactant. Designed as a secondary surfactant. On its own the cleaning power is limited and it does not foam as robustly.

Combining with very high-electrolyte (salt) loads. Sulfosuccinates can precipitate from very salty solutions.

Storage in warm areas. The liquid can develop a slight color or odor over time in warm storage. Cool storage extends shelf life.

Substitutes

• Cocamidopropyl Betaine — workhorse secondary surfactant, very common.
• Coco-Glucoside — non-ionic mild secondary surfactant.
• Decyl Glucoside — non-ionic mild secondary surfactant.
• Sodium Cocoyl Glutamate — primary or secondary mild surfactant.
• Coco-Betaine — closely related to cocamidopropyl betaine.