Menaquinones are isoprenoid quinones of the naphthalene series and belongs to the K2 Vitamin homologs. Menaquinones were originally discovered as the anti-hemorrhagic factor and now encompasses a variety of physiological processes. Menaquinone 4 has four isoprene residue in its side chain and is also commonly refered to as menatetrenone. Menaquinone-4 is the most common type of vitamin K2 and is known as a hemostatic agent and is used as adjunctive therapy for the pain of osteoporosis.