Spirulina is a blue-green micro-algae which grows in alkaline water and is widely used as a dietary supplement (in tablet, flake and powder form). It contains extremely high levels of beta carotene, amino acid and vitamin B-12 and is high in phycocyanins, which give it its characteristic colour and affect the stem cells found in bone marrow. Several recent scientific studies show Spirulina’s ability to inhibit viral replication and strengthen the immune system. It is gaining increasing attention from medical scientists as a nutraceutical and a potential source of pharmaceuticals.