What is Doctor’s Best Lumbrokinase? Doctor’s Best Lumbrokinase provides enzymatic support to help maintain cardiovascular function. Lumbrokinase is the name of a group of highly stable fibrinolytic enzymes. These proteolytic enzymes have been studied and utilized extensively in China for many years. Research suggests that lumbrokinase may have beneficial effects on the cardiovascular system. Fibrinolytic enzymes are essential enzymes that break down excess fibrin in the body. These enzymes eliminate excess fibrin that that forms scar tissue inside blood vessels, kidneys and brain as well as in muscles. Doctor’s Best Lumbrokinase helps break down proteins facilitating the removal of cell debris.