Phosphatidylserine (PS) is a common structural component of biological membranes of plants, animals, and other life forms. Human brain cell membranes are highly enriched with PS. Nerve cells depend on healthy membrane function for normal neurotransmitter metabolism and nerve signal transmission. PS levels ensure membrane fluidity, structure, and therefore function. PS is the most researched, scientifically validated brain health nutrient, shown effective in numerous clinical trials to improve brain focus, memory and cognition, plus alleviating stress and improving mood.