Phosphatidylserine (PS) is a negatively charged glycerophospholipid that is widespread but quantitatively minor phospholipid in mammalian cells. PS is found mainly in animals and white beans. PS is found mostly on the inner layer of the plasma membrane. During cell apoptosis it is redistributed to the outer layer where it functions as a ligand for phagocyte recognition and as an anti-inflammatory.1 In vertebrates, PS is a signal for removal by macrophages. PS is also externalized for various cellular functions such as cell fusion, blood clotting and regulating cell signaling. It acts as an important part of the lipid-calcium-phosphate complex needed for mineral formation.2 PS has been extensively investigated for a number of possible therapeutic roles including treating dementia, relieving stress, and recovering from exercise.3
