L-Alpha glycerylphosphorylcholine is a natural choline compound found in the brain. It is also a parasympathomimetic acetylcholine precursor which may have potential for the treatment of Alzheimer's disease and dementia. Alpha-GPC is also used as a nootropic dietary supplement to enhance memory and cognition. Alpha-GPC rapidly delivers choline to the brain across the blood–brain barrier and is a biosynthetic precursor of the acetylcholine neurotransmitter. Many users report degradation of Alpha-GPC when stored openly or for long periods of time. It should be noted that Alpha-GPC is hygroscopic and will pull moisture in from the surrounding air. Alpha-GPC may be derived from highly purified soy lecithin in small volumes. Industrially, it is produced by the chemical or enzymatic deacylation of phosphatidylcholine enriched soya phospholipids followed by chromatographic purification.