Echinacea is also known as the purple coneflower. Three of the nine species are used medicinally. They are E. angustifolia, E. purpurea, and E. pallida. The first two are most widely used. Echinacea has been used in humans to treat general infections and wounds, colds/flu, candidiasis, strep throat, staph infections, urinary infections, allergies, and toothaches. The active ingredient in echinacea has not yet been identified. It is suspected to work by inhibiting viral and bacterial breakdown of the body's cell walls which is a necessary step before the bacteria and viruses can replicate in the body. It may also slow the growth of some types of tumors.

Echinacea is used in fresh root, dried, tincture, tea, or capsule forms. Doses vary if the product is used at a tonic dose, maintenance dose, protective dose, or full course. Use is often discontinued after a maximum of 6-8 weeks since the immune-promoting impact may fade. Therapy may be started again at a later date. A scratchy throat may show up after extended use in humans.

Do not use if the patient is suffering from autoimmune disorders such as lupus, or tuberculosis, or connective tissue disorders. Not recommended for people with HIV or AIDS; therefore, it probably should not be used in cats with FeLV, FIV, or FIP.