Sucrose stearate is a mixture of the sugar sucrose and a natural substance known as stearic acid. In nature, sucrose is found in most fruits and vegetables. Commonly derived from sugar cane and sugar beets, sucrose is the raw material used to make ordinary white table sugar, a common ingredient in many foods. Stearic acid is a fatty acid found in the fats of many animals as well as in high concentrations in shea butter and cocoa butter.
In skin care products, sucrose stearate can play a wide variety of roles. Within some formulas, sucrose stearate is an important active ingredient, functioning as a skin emollient. An emollient is an ingredient that softens the skin and smooths its texture. The skin is comprised of millions of individual cells. The new, healthy skin cells that are found in the middle layer (dermis) of the skin are typically plump and have very little space between them.
As skin cells are naturally shed, these cells move to the outermost layer (epidermis) of the skin, where they are subjected to the effects of the environment. Older epidermal skin cells are more shriveled and have tiny gaps between them as a result. These tiny spaces are what make the skin feel rough and uneven. When applied to the skin, sucrose stearate fills in these tiny spaces between the cells, improving the skin's texture. This is especially beneficial for dry skin, where the spaces are usually larger than those found in other types of skin. The emollient properties of sucrose stearate make the ingredient popular for use in moisturizers, hand and foot creams and body lotions.
Although the substance is effective as an active ingredient, sucrose stearate is more commonly used as an additive or supportive ingredient in skin care products. The rich texture that allows sucrose stearate to function well as an emollient also makes it useful as a thickener in skin care products and cosmetics. By adding the ingredient to their formulas, manufacturers can make watery products feel more substantial and be easier to apply to the skin. This also gives products a more luxurious, soothing feeling when they are applied.
Due to its chemical structure, sucrose stearate has the ability to bring water-soluble and oil-soluble ingredients together. Ingredients that possess this property are known as emulsifiers. Among the wide array of emulsifiers contained in skin and hair care products, sucrose stearate is considered a moderate to weak one. Typically, the ingredient is used along with another emulsifier to help keep formulas from separating in their packaging; however, it can also be used as the sole emulsifier in products where the risk of separating is not great due to the nature of its ingredients.
In a small number of skin and hair care products, sucrose stearate is added as a preservative, an ingredient that helps to keep formulas potent and pure. Sucrose stearate has the ability to limit the growth of bacteria, mold, mildew and other microbes that can contaminate skin care products before they are purchased and after they are opened. The ingredient's anti-microbial abilities are not as far-reaching as many others available on the market today, which accounts for how infrequently sucrose stearate is used as a preservative.
Clinical research has led to a potential new use for sucrose stearate as an active ingredient in skin care products. A study published in the "Journal of Food Science" in 2002 found that sucrose esters of fatty acids like sucrose stearate have the ability to enhance the activities of antioxidants, nutrients that protect the body from the effects of free radicals. If these initial findings are true, sucrose stearate could make an effective ingredient in anti-aging skin care products that use antioxidants like vitamin C or coenzyme Q10 to protect the skin against the development of fine lines and wrinkles; however, more research is still needed into this potential use of sucrose stearate.
Sucrose stearate is listed as "Generally Regarded as Safe" by the U.S. Food and Drug Administration, and both sucrose and stearic acid have been deemed safe for use in skin care products by the independent review board the Cosmetic Ingredient Review. There is no evidence to suggest that sucrose stearate has any toxic or cancer-causing properties, and the ingredient has not been found to cause skin irritation in clinical studies.