The ongoing coronavirus disease (COVID-19) pandemic has raised the need for new therapies to treat respiratory infections. A bibliographic review based mainly on the databases of the European medication agency (E.M.A) and the Department of Environment and Territorial Policy of the Basque Government (Spain) was carried out. From both databases, it was observed that 14 plant species of the 408 reviewed plants (3%) are approved for medicinal use at European level and that their use, coincides with the most common reasons for consultation in Primary Care. One of these pathologies (common cold) and 2 medicinal plants (Plantago lanceolata and Primula veris) have been selected for the present study. We will determine the efficacy and safety of the two plant species using one randomized multicenter open clinical trial. In the clinical trials, three treatment groups will run in parallel; two treatment groups with medicinal plants and another group with conventional treatment. The of the clinical trial will be: To objectify the therapeutic effects of the medicinal plants using parameters of usual clinical practice in primary care, to evaluate the side effects and the safety of the use of medicinal plants and to rationalize the mechanism of action of the possible benefits.