Amazon.com: Doctor's Best Best Phosphatidyl Serine 100, 120-Count : Health & Household
Amazon.com: NOW Supplements, Phosphatidyl Serine 300 mg, Extra Strength, with Phospholipid compound derived from Soy Lecithin, 50 Softgels : Health & Household
Extra Strength Phosphatidyl Serine, 300 mg, 50 Softgels