Nattokinase (NSK-SD™) Systemic Enzyme for Healthy Circulation Nattokinase is a systemic enzyme isolated from the traditional Japanese soy food natto. It has been shown to support healthy blood flow by assisting the circulatory clearing system of the body.NSK-SD™ is a trademark of Japan Bio Science Laboratories.* 100 mg Capsule Option Available: 30, 60 Suggested Use: 1 capsule three times daily on an empty stomach with 8 ounces of water. Allergies: Contains no yeast, dairy, egg, gluten or wheat. Contains no sugar, salt, preservatives, or artificial color, flavor or fragrance.