Krill oil is unique in that it offers a naturally occurring complex of omega-3 and omega-6 fatty acids, phospholipids and astaxanthin. This phospholipid-fatty acid molecule closely resembles that of human brain phospholipids, providing potential support for cognitive function The essential fatty acids in krill oil may also mediate hormone, prostaglandin, and neurotransmitter function to support menstruating women. A double blind, randomized clinical trial suggested that krill oil promoted physical and emotional well being during the menstrual cycles of women volunteers. Krill oil also provides an ideal essential fatty acid balance for healthy cardiovascular and platelet function. A prospective phase II randomized, double blind, clinical trial suggested that krill oil supports healthy lipid, triglyceride and glucose metabolism. A prospective controlled pilot clinical trial reported that krill oil supplementation helped promote joint flexibility and comfort. In addition, a randomized, controlled pre-clinical trial investigated the effects of krill oil on skin health and reported that it supports the body's natural defenses against the sun and environment.