Answer
The registered indication is considered plausible from longstanding medicinal use; it does not mean clinical trials have conclusively proved effectiveness.
Sources for this answer
- Care Echinacea Cold & Flu Relief Tablets / EchinEeze Echinacea Tablets — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.