A biologically active food additive for normalizing the function of the thyroid gland comprises roots or rhizome or the above-ground part of white cinquefoil, or a mixture thereof, purple echinacca and laminaria, with the following ratio of components in mass %: 10-75 of white cinquefoil, 10-50 of purple echinacea and 10-80 of laminaria. The technical result of the invention is the showing of increased efficacy in treating thyroid gland disorders and enhancing the body's immune status, with no side of effects.