Remedy · supplement
Spirulina
Also: Arthrospira platensis, blue-green algae
An algae supplement with one solid trial for hay-fever symptoms.
Evidence by condition
Each grade reflects the research for Spirulina and that condition specifically.
- CAllergic rhinitis (hay fever)
A 150-patient double-blind trial found spirulina (~2 g/day) reduced nasal discharge, sneezing, congestion, and itching versus placebo, but the overall evidence base is small.
1 citation
- The effects of spirulina on allergic rhinitis Randomized trial 2008 · n=150 · European Archives of Oto-Rhino-Laryngology · PMID 18343939 · DOI 10.1007/s00405-008-0642-8
- The effects of spirulina on allergic rhinitis
Spirulina has a single reasonably sized trial behind its hay-fever claim — encouraging but not yet replicated. Product purity matters, since algae supplements can be contaminated with heavy metals or toxins if poorly sourced.