Myristoyl Sarcosine
What Is It?
The acyl sarcosines (Cocoyl Sarcosine, Lauroyl Sarcosine, Myristoyl Sarcosine, Oleoyl Sarcosine, Stearoyl Sarcosine) are modified fatty acids, and acyl sarcosinates (Sodium Cocoyl Sarcosinate, Sodium Lauroyl Sarcosinate, Sodium Myristoyl Sarcosinate, Ammonium Cocoyl Sarcosinate, Ammonium Lauroyl Sarcosinate) are their respective salts. In cosmetics and personal care products, these ingredients are used in the formulation of shampoos, bath, cleansing and shaving products.
Why Is It Used?
Acyl sarcosines and sarcosinates enhance the appearance and feel of hair, by increasing hair body, suppleness, or sheen, or by improving the texture of hair that has been damaged physically or by chemical treatment. They also clean skin and hair by helping water to mix with oil and dirt so that they can be rinsed away.
Scientific Facts
The acyl sarcosines are prepared from fatty acids and sarcosine, which is a breakdown product of creatine or caffeine. These modified fatty acids impart greater solubility, crystallinity and acidity compared to the parent fatty acid, i.e., coconut acid, oleic acid, lauric acid, and myristic acid.
Safety Information
The Food and Drug Administration (FDA) reviewed the safety of Lauroyl Sarcosine, Stearoyl Sarcosine, and Sodium Lauroyl Sarcosinate and approved their use as indirect food additives for use in cellophane having incidental contact with food. N-Acyl Sarcosines such as Lauroyl, Oleoyl, or Sarcosines with the combined fatty acids of coconut oil have been approved as anti-static and/or anti-fogging agents for food packaging material. The safety of acyl sarcosines and sarcosinates has been assessed by the Cosmetic Ingredient ReviewThe Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. (CIR) Expert Panel.
The CIR Expert Panel evaluated the scientific data and concluded that Cocoyl Sarcosine, Lauroyl Sarcosine, Myristoyl Sarcosine, Oleoyl Sarcosine, Stearoyl Sarcosine, Sodium Cocoyl Sarcosinate, Sodium Lauroyl Sarcosinate, Sodium Myristoyl Sarcosinate, Ammonium Cocoyl Sarcosinate and Ammonium Lauroyl Sarcosinate were safe as used in rinse-off products, and safe for use in leave-on products at concentrations of 5% or less.
The data were insufficient to determine the safety for use in products where the sarcosines and sarcosinates were likely to be inhaled. The CIR Expert Panel cautioned that these ingredients may be susceptible to nitrosamine formation.
CIR Safety Review: The CIR Expert Panel conducted previous safety assessments on each of the fatty acids that appear in these Acyl Sarcosines and Sarcosinates (coconut acid, oleic acid, lauric acid, myristic acid, stearic acid). In each case the fatty acidA natural organic compound that consists of a carboxyl group (oxygen, carbon and hydrogen) attached to a chain of carbon atoms with their associated hydrogen atoms. The chain of carbon atoms may be connected with single bonds, making a ‘saturated’ fat; or it may contain some double bonds, making an ‘unsaturated’ fat. The number of carbon and hydrogen atoms in the chain is what determines the qualities of that particular fatty acid. Animal and vegetable fats are made up of various combinations of fatty acids (in sets of three) connected to a glycerol molecule, making them triglycerides. was safe for use in cosmetic formulations. The acyl sarcosines and sarcosinates had low oral toxicity. They were not mutagenic. These ingredients were nonirritating and nonsensitizing to skin, although they enhanced the penetration of other ingredients through the skin.
The CIR Expert Panel concluded that the acyl sarcosines and sarcosinates were safe as used in rinse-off products. They may be safely used in leave-on products at concentrations up to 5%, the highest concentration tested in clinical irritation and sensitization studies. Because of the absence of data on inhalation toxicity of these ingredients, the CIR Expert Panel concluded that the available data were not sufficient to support the safety of acyl sarcosines and sarcosinates as cosmetic ingredients in products where they are likely to be inhaled.
The CIR Expert Panel also acknowledged that sarcosine may be nitrosated to form N-nitrososarcosine, a potentially carcinogenic compound. Therefore, these ingredients should not be used in cosmetics and personal care products in which N-nitroso compounds may be formed.
More information about nitrosamines.
Link to FDA Code of Federal Regulations for N-acyl sarcosines
The aryl sarcosines and sarcosinates may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European UnionUnder the general provisions of the cosmetics regulation of the EU, ingredients appearing on the following function-specific annexes must comply with the listed restrictions and/or specifications: colorants (Annex IV), preservatives (Annex V), UV filters (Annex VI) and other ingredients with specific concentration limits and/or other restrictions (Annex III). Ingredients specifically prohibited from use in cosmetic products are listed in Annex II. Other ingredients listed in the EU cosmetic ingredient database (CosIng) may be used without restrictions..
More Scientific Information
Cocoyl Sarcosine, Lauroyl Sarcosine, Myristoyl Sarcosine, Oleoyl Sarcosine, Stearoyl Sarcosine, Sodium Cocoyl Sarcosinate, Sodium Lauroyl Sarcosinate, Sodium Myristoyl Sarcosinate, Ammonium Cocoyl Sarcosinate and Ammonium Lauroyl Sarcosinate are all N-acyl derivatives of sarcosine. In cosmetics and personal care products, the acyl sarcosines and their salts function as hair conditioning agents and surfactantAn ingredient that helps two substances that normally do not mix to become dissolved or dispersed in one another. Also called a surface active agent. – cleansing agents.
Resources
Find out more about the regulation of Food Additives by the Food and Drug Administration
- Food Ingredients and Packaging
- Food Contact Substances
- Substances Generally Recognized As Safe (GRAS“GRAS” is an acronym for the phrase Generally Recognized As Safe. Under sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act (the Act), any substance that is intentionally added to food is a food additive, that is subject to premarket review and approval by FDA, unless the substance is generally recognized, among qualified experts, as having been adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excluded from the definition of a food additive.)
- Search the Code of Federal Regulations
- EU Cosmetics Inventory