C18-38 Alkyl Hydroxystearoyl Stearate

What is C18-38 Alkyl Hydroxystearoyl Stearate?

C18-38 Alkyl Hydroxystearoyl Stearate is a high-molecular-weight ester formed by reacting long-chain alcohols (C18 to C38) with hydroxystearic and stearic acids. Produced synthetically, it serves as a multifunctional additive in cosmetic formulations like creams, lotions, and makeup. Primarily used in oil-in-water emulsions, it functions by creating a robust interfacial film around oil droplets, preventing coalescence and maintaining product integrity over time. As a viscosity controller, it builds structure to adjust flow properties, enabling smooth dispensing and even application. Its emollient action involves depositing a light lipid layer on the skin, enhancing slip and reducing friction for a softer feel. This ingredient supports diverse textures from lightweight serums to rich balms without compromising stability.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Emulsion stabilizer
Improves emulsion robustness by preventing droplet coalescence and phase separation, often by thickening, structuring, or strengthening the interfacial layer.
Viscosity controlling agent
Adjusts thickness to the desired level for stability and usability, improving dispensing, suspension, and texture across many formulation types.
Emollient
Softens and smooths skin by filling in surface roughness and improving slip; can also help reduce moisture loss when paired with occlusives and film formers.

Benefits

Helps maintain emulsion stability to prevent separation in creams and lotions.

Adjusts product thickness for improved spreadability and user experience.

Provides mild softening effect by smoothing skin surface irregularities.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Individuals using emulsion-based moisturizers for reliable texture.
Those with rare sensitivities to fatty acid esters.
People seeking thicker formulations that apply smoothly.
People preferring fully natural or plant-derived ingredients only.
Users wanting non-comedogenic options for daily skincare routines.
Individuals experiencing reactions to structurally similar stearates.

Safety Notes

  • Considered low hazard in cosmetic concentrations by safety assessments.
  • Non-comedogenic profile supports use on various skin types.

Frequently Asked Questions about C18-38 Alkyl Hydroxystearoyl Stearate

What does C18-38 Alkyl Hydroxystearoyl Stearate do in products?

It stabilizes emulsions, controls viscosity for better texture, and acts as a mild emollient to soften skin.

Is it safe for sensitive skin?

Safety reviews indicate low hazard and minimal irritation potential in cosmetics.

Does it contribute to acne?

No, with a comedogenic rating of 0, it poses low risk for pore clogging.