There are distinct functions to differentiate depending on the part of the plant being used. Gaia Herbs has extensively researched the activity of the seeds, flowering tops in several phases of development and the roots through a grant sponsored by the National Centers for Complementary and Alternative Medicine. It is important to look for and use products that have been tested for activity and list either Alkylamides or Polysaccharide content on the label, as these constituents are relatively unstable and need to be prepared and delivered properly to maximize efficacy. The flowers when harvested in their early developmental phase contain Arabinogalactin Proteins and Polysachharides. These chemicals support ongoing immune function and are best-used long term for supporting the immune system. The roots harvested in the fall contain large amounts of Alkylamides and support a healthy inflammatory response in the sinuses and are best used at onset, not for long-term use.