See all reviews Sytrinol is a proprietary blend of natural citrus flavones and palm tocotrienols that help support heart health. What makes Swanson Ultra Sytrinol so effective is that it works three different ways to protect your cardiovascular system. First, its polymethoxylated flavones (PMFs) decrease apoprotein B, a structural protein. Second, PMFs decrease levels of liver enzymes needed for synthesis of triglycerides. Third, the palm tocotrienols in Sytrinol inhibit HMG CoA reductase, an enzyme responsible for liver support. This three-pronged approach makes Sytrinol one of the most effective natural supplements to cover your cardio health bases.