Stearic Acid

The Basics On Stearic Acid

What is Stearic Acid?

Also called Octadecanoic Acid, one of the most common long-chain fatty acids, found in both natural animal and vegetable fats and used as an emollient and emulsifier.

What are other names for Stearic Acid?

N-OCTADECANOIC ACID, OCTADECANOIC ACID, and STEARIC ACID

What is Stearic Acid used for?

Stearic acid is regarded as a low-risk skincare formulation ingredient and is safe to use on our skin2. It is approved by the US FDA for use in topical skin formulations1.

How Stearic Acid is classified

Thickeners/Emulsifiers, Emollients, Skin-Replenishing

Recommendations for using Stearic Acid during pregnancy and breastfeeding

Limited data suggests no known risk

 

Stearic Acid During Pregnancy

What we know about using Stearic Acid while pregnant or breastfeeding

Limited information available.

Dermal and oral DART studies of several fatty acid and fatty acid salt ingredients are summarized in Table 13.Lithium Stearate caused no treatment-related adverse reproductive or developmental effects at doses up to 1000 mg/kg bw/day in dermal studies where male rats were treated for 43 days and female rats were treated for 33 days until gestation day 19.28While non-reproductive effects were noted in parental animals in a few oral studies, no treatment-related adverse effects were observed on the reproductive cycles or development of offspring in rats exposed to Behenic Acid (up to 1000 mg/kg/day; males were treated 42 days and females were treated ~39 days until lactation day 3),22 Calcium Stearate (up to 1000 mg/kg/day; males were treated 28 days and females were treated ~39 days until lactation day 3),35 Capric Acid (up to 2000 mg/kg/day; females were treated up to ~33 days until lactation day 4),23 Caprylic Acid (up to 1000 mg/kg/day; females were treated for up to 9 days during gestation starting on gestation day 12),25,60 or Undecylenic Acid (up to 1000 mg/kg/day; males were treated up to 28 days and females were treated up to 40 days until lactation day 4).32Lauric Acid, Myristic Acid, Oleic Acid, Palmitic Acid, Stearic AcidAlthough placental transfer of fatty acids has been documented in several species and fetal lipid metabolism has been studied, no studies on the teratogenicity of Oleic, Lauric, Palmitic, Myristic, or Stearic Acids were found.8 Feeding of 15% dietary Oleic Acid to rats in a chronic study resulted in impairment in the reproductive capacity of female rats. Little or no toxicity to sperm cells in vitro in whole semen samples by serial dilutions of Oleic Acid, Palmitic Acid, and Stearic Acid were observed in studies of these ingredients.9 Magnesium StearateWhen fed to female rabbits at 8 days post-coitus, a pharmaceutical vehicle containing 5.5% by weight Magnesium Stearate was not teratogenic.4Hydroxystearic AcidThe dermal teratogenicity of two antiperspirant prototype formulations containing 7% Hydroxystearic Acid was evaluated using 2 groups of 30 Charles River Crl:CD VAF/Plus female rats on gestation days 6 through 15.5 There were no test article-related or statistically significant differences in the incidence of fetal malformations or fetal developmental variations between experimental and control groups. Skin irritation reactions, however, were observed in greater than 50% of the dams in both experimental groups. No deaths were reported during the study.

General safety info about Stearic Acid from CIR

The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of 102 fatty acids and fatty acid salts, most of which are reported to function as anticaking agents, emulsion stabilizers, viscosity increasing agents, opacifying agents, and surfactants in cosmetic products. The Panel reviewed the available data to determine the safety of these ingredients, noting that these ingredients may cause dermal irritation. Further, the Panel also noted the potential for polyunsaturated fatty acids to undergo oxidation during the formulation of cosmetic products, which may produce compounds that may be dermal sensitizers. The Panel concluded that fatty acids and fatty acid salts are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating and non-sensitizing, which may be determined based on a quantitative risk assessment (QRA).

Use this, not that!

Products where you might find Stearic Acid

N/A