The berries and flowers of elderberry are packed with antioxidants and vitamins that may boost your immune system. They could help tame inflammation, lessen stress, and help protect your heart, too. Some experts recommend elderberry to help prevent and ease cold and flu symptoms.Elderberry extract has been shown to significantly improve or reduce cold and flu symptoms, and it may help you get over your symptoms faster, when taken at the first sign of illness. According to this study, elderberry extract has been shown to reduce the duration of flu symptoms by an average of 4 days