Lecithin

Also known as Phosphatidylcholine (primary component), Soybean lecithin, Soy lecithin, Egg lecithin, E322, Phospholipids from soybean/egg yolk

Lecithin (CAS 8002-43-5) is a naturally-occurring mixture of phospholipids extracted from soybean or egg yolk, primarily composed of phosphatidylcholine with smaller amounts of phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid. In cosmetic formulations it functions as a natural amphiphilic emulsifier, liposome-forming agent (for delivery of lipid-soluble actives), and skin conditioning agent. The phospholipid bilayer structure mimics the stratum corneum intercellular lipid matrix, giving lecithin excellent skin compatibility. The Cosmetic Ingredient Review Expert Panel originally assessed Lecithin and Hydrogenated Lecithin in 2001 (Int J Toxicol 20(Suppl 1):21-45, PMID 11358109) and concluded that Lecithin and Hydrogenated Lecithin are safe as used in rinse-off products and safe in leave-on products at concentrations up to 15% (the highest concentration tested in clinical irritation and sensitization studies). The 2015 amended assessment (CIR Final Report March 2015, subsequently published as Johnson, Bergfeld, Belsito et al., Int J Toxicol 2020, PMID 32975152) expanded the scope to 17 phosphoglyceride ingredients (lecithin, hydrogenated lecithin, lysolecithin, phospholipids, hydrolyzed phospholipids, phosphatidic acid, lysophosphatidic acid, phosphatidylglycerol, lysophosphatidylglycerol, phosphatidylserine, ammonium phosphatidyl rapeseedate, phosphatidylcholine, hydrogenated phosphatidylcholine, hydrogenated lysophosphatidylcholine, lysophosphatidylethanolamine, and phosphatidylinositol) and concluded they are all safe in the present practices of use and concentration. The QRT row records 'S' without a concentration qualifier, reflecting the updated 2015 conclusion. The 2015 assessment flagged one formulation-context restriction: because of the theoretical possibility of nitrosamine formation, lecithin should not be used in cosmetic products in which N-nitroso compounds may be formed (a standard caution that applies to many nitrogen-containing cosmetic ingredients). Lecithin is FDA GRAS as a direct food additive (E322 in the EU) and is widely consumed in its natural form as a component of egg yolk, soybeans, and other dietary phospholipid sources.