Study results are mixed on whether echinacea effectively treats colds or flu.
For example, two NCCAM-funded studies did not find a
benefit from echinacea, either as Echinacea purpurea fresh-pressed juice for treating colds in children, or as an unrefined
mixture of Echinacea angustifolia root and Echinacea purpurea root and herb in adults.
However, other studies have shown that
echinacea may be beneficial in treating upper respiratory infections.
Most studies to date indicate that echinacea does not
appear to prevent colds or other infections.