Phosphatidylcholine
Phosphatidylcholine (PC) is a phospholipid with choline as its head group. With phosphatidylethanolamine, it is the most abundant phospholipid in mammalian cell membranes, and making it is the main fate of choline in the body.
What it means in practice
Mammalian cells make PC from choline through the CDP-choline pathway [3]. The liver has a second route, in which an enzyme called phosphatidylethanolamine N-methyltransferase converts phosphatidylethanolamine into PC [3]. In mice that lack this enzyme, a choline-deficient diet led to fatal liver damage, which the review's authors cite as showing that choline is an essential nutrient [3].
The liver needs PC to secrete very low density lipoprotein (VLDL), a fat-carrying particle [3]. The balance between PC and phosphatidylethanolamine in a tissue can affect energy metabolism and the size of lipid droplets, according to a 2017 review [2]. The general outline of many of the pathways that make phospholipids was set out by Eugene Kennedy and co-workers in the 1950s [2].
PC also feeds other molecules. Cells use it to make phosphatidylserine by swapping the head group for serine [4].
Why it matters when reading nootropics research
PC comes up in research on choline supplements. A Cochrane review describes CDP-choline, called citicoline when given as a drug, as a precursor essential for making PC [5]. The European Food Safety Authority describes alpha-GPC as a natural breakdown product of PC, and the alpha-GPC it assessed was made from soy lecithin enriched in PC [6].
These are statements about chemistry. Being part of the PC pathway does not by itself show that a supplement changes memory or attention; each compound's page reports the human trials separately.
References
- Lamari F, Rossignol F, Mitchell GA. Glycerophospholipids: Roles in Cell Trafficking and Associated Inborn Errors. J Inherit Metab Dis. 2025.
- van der Veen JN, Kennelly JP, Wan S, et al. The critical role of phosphatidylcholine and phosphatidylethanolamine metabolism in health and disease. Biochim Biophys Acta Biomembr. 2017.
- Li Z, Vance DE. Phosphatidylcholine and choline homeostasis. J Lipid Res. 2008.
- Kim HY, Huang BX, Spector AA. Phosphatidylserine in the brain: metabolism and function. Prog Lipid Res. 2014.
- Fioravanti M, Yanagi M. Cytidinediphosphocholine (CDP-choline) for cognitive and behavioural disturbances associated with chronic cerebral disorders in the elderly. Cochrane Database Syst Rev. 2005.
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Bohn T, et al. Safety of L-alpha-glycerylphosphorylcholine (L-alpha-GPC) from soya phospholipids (lecithin) as a novel food pursuant to Regulation (EU) 2015/2283. EFSA J. 2026.