Spirulina is a type of blue-green algae that is consumed as a nutritional supplement. It contains high amounts of protein, B vitamins, iron, and other nutrients. Spirulina also contains antioxidants like phycocyanin that can help reduce oxidative damage, inflammation, and protect heart health. Some key benefits of spirulina include its high nutritional value, antioxidant properties, ability to improve strength, protect the heart, and help with anemia.