What are spirulina's health benefits?

Spirulina may help relieve nasal congestion and rhinitis symptoms, likely in part through anti-inflammatory effects.

• 1. Nasal symptoms and sleep: In two randomized, double-blind human studies, spirulina was associated with reduced nasal obstruction and itching, better ability to smell, improved sleep, and lower inflammatory cytokines. The cited dose was 2 grams, and the effects could take a short while to appear. 1
• 2. Possible mechanism: Spirulina may inhibit the formation or activity of histaminergic mast cells, which release histamine and contribute to swelling and inflammation in allergic reactions. 2