Elderberry comes from the herb known as Sambucus nigra or Black elder. It is has many medicinal properties that are especially useful during cold and flu season. The berries are anti-viral and contain high amounts of vitamin C and other antioxidants: flavinoids and anthocyanins. The anthocyanins found in the berry have been shown to enhance cytokine production; cytokines are proteins involved in the body's immune response, thereby enhancing the body's defense against infection. Scientists have found that the antioxidant capacity of elderberry is more than that of vitamin C on its own making it useful beyond immune boosting properties. The high antioxidant content helps to improve the tone of blood vessels and crosslinking of collagen as well as help fight against cell damage. 

Conventionally, cold and flu is treated with drugs or vaccines from a class of drugs known as neuraminidase inhibitors. Studies have found the flavinoid content of the elderberries to exhibit this same neuraminidase-inhibiting effect the drugs commonly used making elderberry extract a viable alternative treatment. *From the BMC Complementary and Alternative Medicine Journal.

I recommend patients take elderberry syrup upon the first signs of a cold coming on as it is most effective when taken in the early stages.