STEARIC ACID

Stearic Acid: What It Is, Properties, Uses and Bulk Supply

Stearic acid is one of the most widely used fatty acids in cosmetic manufacturing. Present in many natural fats and vegetable oils, it has become a workhorse ingredient for laboratories formulating creams, lotions, balms and bar soaps. Its chemical formula, C18H36O2, places it among the saturated fatty acids, and its physical and emollient properties make it a key building block in countless personal care products. In this guide we explain what stearic acid is, what its main characteristics are, how it behaves in cosmetic formulations, where it is typically used and how to source it in bulk from a European B2B supplier like Royal Bio.

What is stearic acid?

Stearic acid, with the chemical formula C18H36O2, is a saturated fatty acid found in fats and oils of both vegetable and animal origin. As a free fatty acid, it appears as a solid, white waxy substance at room temperature. It is insoluble in water but readily soluble in many organic solvents, which is consistent with its long hydrocarbon chain and limited polarity.

The compound belongs to the family of long-chain saturated fatty acids, and is widely available as a cosmetic-grade raw material in the form of flakes, beads or powder. Its high availability, well-established safety profile and predictable behaviour during processing have made it one of the most common functional ingredients in cosmetic manufacturing.

From a technical perspective, stearic acid is appreciated by formulators because it consistently delivers structure, body and a pleasant after-feel to a wide variety of cosmetic systems, from light lotions to dense balms.

Key properties of stearic acid

Stearic acid is endowed with emollient properties, which means it contributes a soft and smooth feel when incorporated into cosmetic products. This characteristic is one of the main reasons it is so often included in skin care formulations.

In addition to its emollient behaviour, stearic acid plays a crucial role in the stability and texture of creams and lotions. When combined with water, oils and other ingredients in an emulsion, it helps build a consistent structure, supports thickening and contributes to the long-term stability of the product. This is particularly important for industrial production, where formulators need ingredients that perform predictably batch after batch.

Because it is a solid at room temperature and melts at moderate temperatures, stearic acid is also valued as a consistency factor. It allows formulators to control the firmness of a product, from a light lotion to a richer cream or a solid balm, without having to rely solely on waxes.

Stearic acid in cosmetic formulation

In modern cosmetic formulation, stearic acid is commonly used in cosmetic products to impart consistency and smoothness. It appears in creams, lotions, body butters, hand creams, face moisturisers, deodorant sticks, shaving creams and many other product categories where a creamy, comforting feel is desired.

It is also a classic ingredient in the production of bar soaps and shaving soaps, where it contributes to a denser, more stable lather and a harder finished bar. In syndet bars and combination soap systems, stearic acid often appears alongside other fatty acids to fine-tune hardness and skin feel.

Beyond its functional role, stearic acid is appreciated for being well known to regulators and well documented in cosmetic safety dossiers. This makes it a convenient ingredient when preparing the safety assessment of a finished cosmetic product under EU regulation.

CAS: 57-11-4. EINECS: 200-313-4. INCI: STEARIC ACID.