Answer
It is registered for symptom relief, not as a cure. Its indication is based on longstanding traditional use rather than proof of effectiveness.
Sources for this answer
- Benylin Herbal Cough & Cold Sugar Free Syrup — Current selected SmPCemc · Summary of Product Characteristics
- UK GovernmentUK Government · Reputable Web
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.