Vitamin K2 is a series of molecules known as menaquinones, some of which are found naturally in fermented soybeans. Thorne Research’s vitamin K2 is MK-4, the most common and well studied of the menaquinones. Vitamin K2, working in concert with vitamin D, exerts a more powerful influence on bone than does vitamin K1.Recommended Dose:(Adults 19 years and over): Take 1 drop daily or as recommended by a health-care practitioner.Risk Information:Consult a health-care practitioner prior to use if you are taking blood thinners