Sodium Lauroyl Methyl Isethionate
Also known as: Sodium Lauroyl Methyl Isethionate, SLMI, Sodium Lauroyl Methylisethionate
Overview
Sodium Lauroyl Methyl Isethionate (SLMI) is a synthetic surfactant derived from lauric acid and sodium isethionate. It is produced through an esterification process, often optimized for environmental and industrial efficiency. Primarily used in personal care products such as shampoos, body washes, and facial cleansers, SLMI is valued for its mild cleansing and foaming properties. It is known for good skin compatibility and can achieve high purity (up to 98%) through recrystallization. Research on SLMI focuses on its chemical synthesis, safety in topical applications, and environmental impact. It is not classified as a dietary supplement and there is no evidence supporting its use or efficacy as an oral supplement. Its main application is as a gentle cleansing agent in cosmetic formulations, making it suitable for individuals with sensitive skin.
Benefits
As a surfactant, SLMI's primary benefit is providing effective cleansing and foaming without causing harsh irritation, making it highly suitable for formulations designed for sensitive skin. This mildness is supported by safety data from regulatory bodies. There are no documented systemic health benefits or effects related to oral supplementation, as SLMI is not intended for internal use. Its benefits are limited to its immediate topical cleansing effect. It is particularly beneficial for individuals with sensitive skin or those who require mild cleansing agents in their personal care routine. The mildness and skin compatibility are key advantages over more traditional, harsher surfactants.
How it works
Sodium Lauroyl Methyl Isethionate functions as a surfactant by significantly reducing the surface tension of water. This property allows it to effectively emulsify oils and dirt, enabling their removal from the skin and hair during cleansing. Its mechanism of action is purely topical, involving the physical interaction with the skin's surface to lift and wash away impurities. There is no evidence of systemic absorption or biological activity within the body. Consequently, SLMI does not interact with internal body systems or have known molecular targets beyond its surfactant activity on the skin's surface.
Side effects
Sodium Lauroyl Methyl Isethionate is generally considered safe for topical use in cosmetic products at typical concentrations. Common side effects are not reported, and there is no documented evidence of uncommon or rare side effects such as irritation or sensitization at typical use levels. The Cosmetic Ingredient Review (CIR) panel has evaluated related sodium isethionate salts and established a no observed adverse effect level (NOAEL) of 200 mg/kg body weight/day in animal studies for systemic exposure, which is well above typical topical exposure. No drug interactions or contraindications are known for its topical application. While specific studies on pregnant or lactating women are not available, animal studies on sodium isethionate have not shown teratogenic effects. Overall, its safety profile for topical use is favorable, with minimal risk of adverse reactions.
Dosage
Sodium Lauroyl Methyl Isethionate is not applicable for oral dosing as it is not a dietary supplement. It is used as an ingredient in personal care formulations, typically ranging from 5-15% concentration in products like shampoos, body washes, and facial cleansers. The minimum effective dose is not relevant in a systemic sense, as its action is topical. The maximum safe dose, based on animal studies of related sodium isethionate compounds, indicates a NOAEL of 200 mg/kg/day, which is significantly higher than any potential systemic exposure from topical use. It is incorporated into liquid or solid cleansing products and used during regular cleansing routines. Minimal systemic absorption is expected from topical application, and no cofactors are required for its function.
FAQs
Is Sodium Lauroyl Methyl Isethionate safe for sensitive skin?
Yes, it is considered a mild surfactant with good skin compatibility, making it suitable for sensitive skin formulations and reducing the likelihood of irritation.
Can it be taken orally as a supplement?
No, there is no evidence or recommendation for oral ingestion. Sodium Lauroyl Methyl Isethionate is strictly intended for topical use in personal care products.
Does it cause irritation?
Generally, no. Safety reviews indicate a low irritation potential at typical use levels in cosmetic products, making it a preferred choice for gentle formulations.
How does it compare to other surfactants?
It is generally considered milder and less irritating than many traditional surfactants, such as sodium lauryl sulfate, offering a gentler cleansing experience.
Research Sources
- https://journals.sagepub.com/doi/pdf/10.1177/1091581816685552 – This comprehensive safety review by the Cosmetic Ingredient Review (CIR) Expert Panel evaluated 12 isethionate salts, including compounds closely related to SLMI. It established a No Observed Adverse Effect Level (NOAEL) of 200 mg/kg/day in animal studies, noting liver changes only at very high doses. The panel concluded these ingredients are safe for cosmetic use at current concentrations, with no observed mutagenic or teratogenic effects.
- https://eprints.whiterose.ac.uk/id/eprint/128372/8/M%20Jeraal%20-%20ACS%20Paper%20(Final).pdf – This study details an improved, environmentally friendly synthesis method for SLMI, achieving high purity (98%) suitable for industrial scale. It highlights SLMI's mildness and skin compatibility as a surfactant, focusing on its chemical and industrial properties rather than clinical outcomes.
- https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-lauroyl-1-methyl-isethionate – The PubChem database entry provides chemical and structural data for Sodium Lauroyl Methyl Isethionate. It serves as a reference for its molecular properties but does not contain clinical or safety data relevant to its use as a supplement or in human trials.