Sugar Free Sambucus Standardized Elderberry by Nature's Way features delivers year-round defense. The high potency of BioActives constituents in Nature's Way Sambucus standardized black elderberry extract are proven to be "bioavailable" and active within the body for optimal effectiveness. For centuries the dark berries of European black elder (Sambucus nigra L.) have been traditionally used as a winter remedy. In recent years, medical researchers have proven its efficacy in clinical trials.