The fungus Cordyceps is native to East Asian countries, notably China, Japan, Korea, Vietnam and Thailand. Cordyceps has anti-aging properties and has been found to provide people with a better exercise regimen through energy and nutrient provision. Cordyceps may improve stamina, appetite, endurance, libido, energy and sleeping patterns. It also stimulates specific chemicals and cells in the body, which in turn improves the immune system. Cordyceps fights mental fatigue by increasing oxygen levels and blood flow to the brain. It can make you feel more focused and alert.