Echinacea whole plant tincture! Young new leaves harvested in the spring, flowers harvested in the peak of summer and then the roots gentle dug up in the fall.
A powerful immune modulator that can increase the body's white blood cells. Not to be taken as a preventative! But very useful for acute viral or bacterial infections (bronchitis, streptococcus, staphylococcus, rhinitis, sinusitis, tonsillitis, and laryngitis for example).
Take precautions if you have a history of auto-immunity as sometimes a "boost to the immune system" is not what you want or need!