Zinc: Zinc inhibits the reproduction of rhinovirus, and has been found to be especially good for treating viral sore throats. A recent study on the effectiveness of zinc showed that taking a zinc lozenge every 2-3 hours, shortened the duration of cold symptoms. Overdosing with zinc can have side effects, such as an effect on the uptake of iron.
Dosage: one lozenge every 2-3 hours for duration of the cold or flu. Keep in the mouth for 5-10 minutes. Or 30 to 50 milligrams a day.

 

Echinacea: Echinacea has powerful antiviral and immunity-boosting effects. It is used to rev up the immune system at the first sign of a cold. Echinacea has been found to work better before you get sick, to build up immunity. It has not been found as effective for treating a cold or flu.
Dosage: take daily according to manufacturers instructions. Take daily during the fall and winter months.

Garlic is great as a preventative and as a treatment. Take two tablets three times a day until the mucus production has slowed down dramatically, or until the color of mucus becomes clear rather than yellow or green. Garlic can also help treat ear infections. Squeeze a garlic clove until the juice runs into a cotton ball and place the cotton ball in the ear. Raw garlic has antifungal, antibacterial, and antiviral properties. Researchers in England found that garlic can speed up recovery from a cold and increase resistance. Study participants had half the number of colds and made a more rapid recovery.

This herb is known to support the immune system and to stimulate the body's ability to fight viruses. Elderberries have been used in medicine since the Fifth Century, for treating the flu and ill effects of the chills, and have been referred to by Hippocrates, Dioscurides and Plinius. Even Shakespeare mentions it in his play The Merry Wives of Windsor: "What says my Aesculapius? My Galen? My heart of Elder?" Studies have shown elderberry to inhibit replication of human influenza virus type A, type B and animal strains from swine and turkeys in cell cultures and to reduce the duration of the flu by approximately four days.