Sodium Cocoyl Isethionate—usually shortened to SCI—is a cleansing surfactant used in personal-care products. If you have seen the ingredient on a gentle cleansing bar, facial cleanser, or solid body wash, its main job is to help water remove oil, sweat, and everyday soil from the skin.
SCI is a surfactant
Water and oil do not mix easily on their own. Surfactants have molecular structures that interact with both water and oily material. During washing, that helps loosen and disperse material so it can be rinsed away.
SCI is an anionic surfactant and is widely used in rinse-off cosmetic formulations. The Cosmetic Ingredient Review (CIR) Expert Panel has evaluated Sodium Cocoyl Isethionate and related isethionate ingredients as part of its cosmetic-ingredient safety review process. (Cosmetic Ingredient Review: Sodium Cocoyl Isethionate)
Why is SCI common in syndet bars?
Solid syndet bars need a surfactant system that can be processed into a durable bar, create satisfying lather, rinse well, and be formulated to an appropriate pH. SCI is useful because it can contribute to a dense, creamy lather and works in soap-free cleansing systems.
It is important not to turn one ingredient into a miracle claim. A cleanser containing SCI is not automatically mild simply because SCI appears on the label. The amount used, the other surfactants, the pH, fragrance, emollients, manufacturing process, and how the product is used all affect the final experience.
SCI versus traditional soap
SCI is not an alkali salt of a fatty acid produced by traditional saponification, so a cleansing system built around SCI can be formulated as a syndet rather than a traditional soap base.
That gives formulators the ability to build a solid cleanser at a lower pH than traditional soap. Reviews of cleanser science generally find that well-formulated mild syndets can be less disruptive than harsh alkaline soap, while also emphasizing that the complete surfactant system matters. (Skin Cleansing without or with Compromise)
How HARP® uses SCI
HARP® uses Sodium Cocoyl Isethionate as the primary surfactant in its 100% syndet, soap-free body wash bar base. The bars are formulated at pH 5.0–6.0.
The combination is intentional: a modern surfactant system, a pH range close to the skin’s mildly acidic surface, and a solid bar format.
What should shoppers look for besides SCI?
- The complete surfactant system: one ingredient does not tell the whole story.
- pH: useful information, but not a substitute for good formulation.
- Fragrance: especially relevant for people with fragrance allergy or very reactive skin.
- How skin feels after repeated use: comfort matters more than marketing terminology.
To understand where SCI fits into the larger cleanser picture, read What Is a Syndet Bar? and Soap vs. Syndet.
Educational note: This article explains cosmetic ingredient function and is not medical advice.
