Soy-Free Cogni-PS - Phosphatidylserine Dietary Supplement Sharp-PS Green Phosphatidylserine (PS) is a naturally-occurring phospholipid and is a component of cell membranes. Jarrow Formulas Cogni-PS is a concentrated form of phosphatidylserine from sunflower lecithin that offers superior stability, does not contain soy and is not derived from genetically modified organisms (non-GMO).