Stearic Acid

Benefits
MoisturizingSoftening
Concerns
Malassezia Feeding

What is Stearic Acid?

Stearic acid is a saturated fatty acid with an 18-carbon chain, naturally derived from animal fats like tallow or vegetable sources such as palm kernel oil and cocoa butter. In cosmetics, it serves primarily in emulsion-based products like creams, lotions, and cleansers. It functions by reducing surface tension between oil and water phases, forming stable interfaces that prevent separation and provide a smooth texture. As a thickening agent, it enhances product viscosity, improving spreadability and feel. In cleansing formulations, it aids in dirt removal and lipid replenishment post-wash. Its waxy nature contributes to barrier support without greasiness, making it versatile across rinse-off and leave-on items.

Comedogenic Rating 3/5 Higher risk of clogging pores
EWG Safety Rating 1 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Fragrance ingredient
Contributes scent character and/or masks base odors, shaping the overall sensory experience of the formula (subject to allergen and IFRA considerations).
Surfactant
Lowers surface tension to enable cleansing, emulsifying, and foaming; central to shampoos, body washes, and many emulsions and micellar systems.
Cleansing agent
Removes dirt, oil, and impurities by lowering surface tension and forming micelles, enabling soils to be lifted and rinsed away from skin, hair, or teeth.
Emulsifying agent
Enables stable mixing of oil and water phases by forming an interfacial film, helping create lotions, creams, and cleansers with consistent texture.
Emulsion stabilizer
Improves emulsion robustness by preventing droplet coalescence and phase separation, often by thickening, structuring, or strengthening the interfacial layer.
Masking
Reduces perception of unpleasant odors or tastes by neutralizing them or covering them with more acceptable sensory notes.
Refatting
Replenishes lipids removed during cleansing to improve mildness and reduce tightness, leaving skin or hair feeling less stripped after rinse-off use.

Benefits

Supports moisture retention for smoother skin texture.

Helps stabilize emulsions for consistent product performance.

Replenishes skin lipids after cleansing to reduce dryness.

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 with dry or normal skin seeking emollient effects.
People with oily skin due to potential pore-clogging.
People using cream-based moisturizers or lotions.
Acne-prone individuals sensitive to moderately comedogenic ingredients.
Those preferring formulations with natural fatty acid-derived stabilizers.
Those prone to fungal issues like malassezia overgrowth.

Safety Notes

  • Rated low hazard by EWG with scores of 1.
  • Deemed safe for cosmetic use by regulatory reviews.

Frequently Asked Questions about Stearic Acid

What is stearic acid derived from?

It comes from natural sources like animal fats and vegetable oils such as palm and cocoa butter.

Is stearic acid comedogenic?

It has a moderate comedogenic rating of 3, so caution advised for oily or acne-prone skin.

Can stearic acid cause irritation?

Evidence indicates low irritation risk in typical cosmetic concentrations.