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SODIUM COCOYL ISETHIONATE

Also known as: SCI, sodium cocoyl isethionate, Sodium Cocoyl Isethionate

Overview

Sodium Cocoyl Isethionate (SCI) is a synthetic surfactant derived from coconut fatty acids and isethionic acid, primarily used in personal care products. It is not a dietary supplement but a topical cleansing agent known for its mildness. SCI is widely incorporated into shampoos, body washes, and facial cleansers due to its ability to produce a creamy lather while being less irritating than harsher surfactants like sodium lauryl sulfate (SLS). Research on SCI mainly focuses on its safety and irritancy in topical applications, with evidence primarily from safety assessments and irritancy studies rather than clinical trials or systemic supplementation studies. It is valued for its gentle cleansing properties and suitability for sensitive skin.

Benefits

SCI is primarily recognized for its mild cleansing effect with significantly lower skin and ocular irritation compared to other anionic surfactants such as SLS. Human volunteer studies have shown that SCI causes less skin barrier disruption and lower irritancy scores than SLS, making it particularly beneficial for individuals with sensitive skin or those prone to irritation from conventional surfactants. It also supports skin barrier recovery better than harsher surfactants. While quantitative irritancy rankings place SCI as less irritating than SLS, exact effect sizes and confidence intervals are not consistently reported. The benefits are observed over short-term application periods (days to weeks) in controlled testing.

How it works

As a surfactant, Sodium Cocoyl Isethionate (SCI) functions by reducing the surface tension of water, which allows it to effectively emulsify and remove oils and dirt from the skin surface. Its action is purely physicochemical and localized to the skin and eyes. SCI does not have specific molecular targets, nor does it undergo systemic absorption or metabolic activity within the body. Its mechanism is limited to its topical interaction with the skin, facilitating cleansing without systemic effects.

Side effects

Sodium Cocoyl Isethionate (SCI) is generally considered a mild surfactant with a favorable safety profile for topical use. Common side effects, occurring in some cases, include mild skin or ocular irritation, especially at higher concentrations (typically above 2.5% to 15%). Moderate ocular irritation may occur at concentrations around 15%. No significant rare adverse effects have been reported. Due to its topical use and minimal systemic absorption, there are no reported drug interactions. Contraindications include individuals with known hypersensitivity to SCI or related surfactants. While generally safe for sensitive skin, ocular exposure should be minimized due to its potential for mild irritancy.

Dosage

Sodium Cocoyl Isethionate (SCI) is typically used in personal care formulations at concentrations ranging from 2% to 15%. For effective cleansing with minimal irritation, a concentration of 2-5% is often sufficient. Higher concentrations, particularly above 15%, may increase the risk of moderate ocular irritation, and formulations rarely exceed this level. SCI is used as needed in daily cleansing routines and is commonly formulated into solid bars, liquid cleansers, and foaming products. As it is a topical ingredient with negligible systemic absorption, there are no systemic dosing recommendations, absorption factors, or required cofactors.

FAQs

Is SCI safe for sensitive skin?

Yes, SCI is considered milder than many other surfactants and is often recommended for individuals with sensitive skin due to its low irritation potential.

Can SCI cause eye irritation?

At concentrations above 2.5%, SCI can cause mild to moderate ocular irritation. Care should be taken to avoid direct eye contact during use.

Is SCI biodegradable?

Yes, SCI is readily biodegradable under aerobic conditions, with studies showing 78-99% degradation, indicating its environmental safety.

Is SCI absorbed systemically?

No, SCI acts locally on the skin surface with negligible systemic absorption, meaning it does not enter the bloodstream or affect internal body systems.

Research Sources

https://cir-reports.cir-safety.org/view-attachment/?id=cd307d65-8e74-ec11-8943-0022482f06a6 – This safety assessment report, including human volunteer studies, found that SCI exhibited mild skin irritation, ranking less irritating than SLS but more than some milder surfactants. Ocular irritation was mild to moderate at concentrations above 2.5%. The study involved 25 volunteers in short-term patch tests, providing moderate quality evidence for SCI's irritancy profile.
https://journals.sagepub.com/doi/pdf/10.1177/1091581816685552 – This source provides further details on the safety and irritancy assessment of SCI, supporting its mild profile. It reinforces the findings that SCI is less irritating than common surfactants like SLS, making it suitable for sensitive skin applications. The report compiles various safety data, contributing to the overall understanding of SCI's dermatological impact.
https://pubmed.ncbi.nlm.nih.gov/17598025/ – This experimental study focused on the impact of SCI on the skin barrier. It found that SCI causes less disruption to skin barrier function compared to harsher surfactants, which supports its mildness and suitability for sensitive skin. While specific sample sizes were not detailed, the study provides mechanistic insights into SCI's gentle action on the skin.
https://19january2021snapshot.epa.gov/sites/static/files/2015-07/documents/c16590tp.pdf – This document from the US EPA details standardized biodegradation tests for SCI. The studies, conducted under GLP conditions with laboratory microbial cultures over 28 days, demonstrated that SCI is readily biodegradable, achieving 78-99% degradation under aerobic conditions. This indicates a high quality of environmental safety data for SCI.