GPC or GlyceroPhosphoCholine is an orthomolecular nutritional important for cell-level homeostasis, tissue growth and renewal, organ vitality, and mind-body integration. GPC is said to provide unique osmo-protection against toxic buildup inside cells. GPC supports metabolic efficiency: enzymes combine GPC specifically with the omega-3 fatty acid DHA to create phospholipids essential to cell membranes. GPC is also a highly bioavailable source for both the essential nutrient choline and the ubiquitous chemical transmitter acetylcholine. Double-blind clinical research reports that GPC boosts attention in healthy youth and counters cognitive decline in middle age. In old age GPC helps revitalize growth hormone, and enables brain-body integration. GPC may also support male fertility and is an important functional constituent of human breast milk.