Phosphatidylserine

Phosphatidylserine (PS) is the predominant anionic phospholipid of the inner leaflet of neuronal cell membranes, constituting approximately 10–20% of total brain phospholipid content. As a structural membrane component, PS maintains membrane fluidity and the negative surface charge critical for voltage-gated ion channel function, receptor clustering, and neurotransmitter vesicle fusion. PS activates protein kinase C (PKC) — the signal transduction enzyme governing synaptic plasticity, long-term potentiation, and memory consolidation. In two FDA-qualified health claims, PS supplementation is associated with reduced risk of cognitive dysfunction in the elderly. Crucially, PS is the physiological inhibitor of the ACTH-cortisol stress axis, with 400–800 mg/day blunting exercise- and psychological stress-induced cortisol elevations by up to 30%.