Validation of a Traditional Medicine, <em>Achyrocline satureioides</em> Infusion, for the Improvement of Mild Respiratory Infection Symptoms: A Randomized, Placebo‐Controlled, and Open‐Label Clinical Trial

Background/Objectives: The need for scientific validation of traditional and folk medicine knowledge has been raised recently. Achyrocline satureoides inflorescences has been widely used for the management of mild viral respiratory infection symptoms in South Brazil, Uruguay, and Argentina. We aim to evaluate the clinical efficacy of a 14-day course with Achyrocline satureoides on mild viral respiratory infection symptoms. Methods: We conducted a randomized, open-label, placebo-controlled trial. Participants were randomized before diagnostic testing for COVID-19 (SARS-CoV-2) into two experimental groups, A. satureioides or Malus domestica infusions and were instructed to use the infusions twice a day for 14 days. Our primary endpoint was the recovery time for respiratory symptoms in the overall analysis, secondary outcomes were the recovery time for non-respiratory symptoms and for stratified analysis, considering vaccination status against SARS-CoV-2 and COVID-19 infection, and the rate of symptom recovery was also evaluated. Results: A. satureioides infusion significantly accelerated the resolution of sore throat and sneezing compared to the control group. Participants with COVID-19 who had not been vaccinated and received A. satureioides infusion recovered faster for sore throat, body ache, fever, and cough also, and the median survival time of resolution. The SARS-CoV-2 negative group receiving A. satureioides showed faster improvement in survival analysis of sore throat, earache and loss of appetite. Conclusions: Our results support the hypothesis that A. satureioides inflorescence infusion may offer benefits in mild viral respiratory infections, because this traditional approach induced significantly faster recovery of symptoms.