Fatty acids are the building blocks from which fats and oils are made. Certain fatty acids are considered "essential" because they cannot be produced by the body and must be obtained from other sources. Krill oil contains significant amounts of the omega-3 fatty acids EPA and DHA. Krill oil is shown to support cardiovascular health by maintaining healthy cholesterol levels. In conjunction with statin therapy, it helps lower triglycerides/triacylglycerols and LDL cholesterol, and helps increase HDL cholesterol levels. It may also play a role in reducing inflammation that characterizes conditions such as arthritis. And it has been shown to help in the management of symptoms of premenstrual syndrome (PMS) and dysmenorrhea (painful menstruation).