Rational and Safe Use of the Top Two Botanical Dietary Supplements to Enhance the Immune System

The recent COVID-19 pandemic has sparked great interest in strengthening the immune system, especially by the consumption of widely available natural dietary supplements. Because of this popularity, it was suggested that the sales of these products would grow significantly in the year 2021, especially for those who are unable or unwilling to receive COVID-19 vaccines. Among the many botanicals, Sambucus nigra L. (Elderberry) and Echinacea purpurea (L.) Moench (Echinacea) have especially shown great popularity. Various in vivo and in vitro tests of S. nigra and E. purpurea extracts and constituents have confirmed the botanicals' influence on proinflammatory cytokines, viral infections, and flu symptoms, proving their immunomodulatory and antiviral effects. Although there have been promising results with S. nigra and E. purpurea containing supplements, thorough monitoring of the sanitary production, demand, and related side effects after consumption is required. Further research and development of the supplements in accordance with the pandemic are also advised.