Costus-D Syrup is a well-balanced combination formulation containing Chlorpheniramine Maleate, Dextromethorphan Hydrobromide, and Phenylephrine Hydrochloride. It is designed to provide effective symptomatic relief from cough, cold, and allergic respiratory conditions. Dextromethorphan acts centrally to suppress the cough reflex, helping to reduce persistent dry cough. Chlorpheniramine Maleate, an antihistamine, alleviates allergy-related symptoms such as sneezing, runny nose, and watery eyes, while Phenylephrine Hydrochloride functions as a nasal decongestant by reducing mucosal swelling and relieving nasal blockage. This synergistic combination helps improve breathing comfort and overall respiratory well-being.