Spirulina, always a Persian staple, contains an unusually high amount of protein, between 55% and 77% by dry weight, depending upon the source. It is a complete protein, containing all essential amino acids, superior to typical plant protein, such as that from legumes.
Spirulina is rich in gamma-linolenic acid (GLA), and also provides alpha-linolenic acid (ALA), linoleic acid (LA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA).
Spirulina contains many pigments including chlorophyll-a, xanthophyll, beta-carotene, echinenone, myxoxanthophyll, zeaxanthin, canthaxanthin, diatoxanthin, hydroxyechinenone, beta-cryptoxanthin, oscillaxanthin, plus the phycobiliproteins , c-phycocyanin,allophycocyanin.
Spirulina helps prevent heart damage caused by chemotherapy using Doxorubicin, without interfering with its anti-tumor activity. Spirulina reduces the severity of strokes and improves recovery of movement after a stroke; reverses age-related declines in memory and learning; and prevents and treats hay fever.
Spirulina is effective for the clinical improvement of melanosis and keratosis due to chronic arsenic poisoning; improves weight-gain and corrects anemia in both HIV-infected and HIV-negative undernourished children; and protects against hay fever.
A 2007 study found that 36 volunteers taking 4.5 grams of spirulina per day, over a six week period, exhibited significant changes in cholesterol and blood pressure: (1) lowered total cholesterol; (2) increased HDL cholesterol; (3) lowered triglycerides; and (4) lowered systolic and diastolic blood pressure.
Spirulina has also been found to be clinically effective against allergic rhinitis, a condition that can lead to chronic sinusitis.