Echinacea supports the immune system through a variety of mechanisms. The extracts are standardized to specific levels of marker compounds known to have immune-enhancing effects. Caffeic acid derivatives (echinacosides), polysaccharides, polyacetylenes, alkylamides and flavonoids are among the plant constituents with known activity. Not manufactured with yeast, wheat, gluten, soy, corn, milk, egg, fish, shellfish or tree nut ingredients.