Flavonoids, including quercetin, are believed to account for the therapeutic actions of the elderberry flowers and berries. These flavonoids include anthocyanins that are powerful antioxidants and protect cells against damage according to test tube studies.¹ According to laboratory research, an extract from the leaves, combined with St. John’s wort and soapwort, inhibits the influenza virus and herpes simplex virus.² The effect on influenza of a syrup made from the berries of the black elderberry has been studied in a small double-blind trial.³ People receiving an elderberry extract (2 tablespoons [30 ml] per day for children, 4 tablespoons [60 ml] per day for adults) appeared to recover faster than did those receiving a placebo. Animal studies have shown the flowers to have anti-inflammatory properties.⁴ These actions have not been verified in human clinical trials.