Grilinctus-L Oral Suspension is a cough suppressant. It is primarily used to treat dry cough. A cough is a reflex action that helps to clear any foreign irritant or mucus in the throat. Dry cough refers to a cough where there is no mucus or secretion along with cough. The most common causes of cough are cold/flu, asthma, emphysema, and COPD (chronic obstructive pulmonary disease).