Dextromethorphan is a cough suppressant which relieves cough by reducing the activity of cough center in the brain. Ambroxol is a mucolytic which thins and loosens mucus (phlegm), making it easier to cough out. Chlorpheniramine Maleate is an antiallergic which relieves allergy symptoms like runny nose, watery eyes and sneezing. Phenylephrine is a decongestant which narrows the small blood vessels providing relief from congestion or stuffiness in the nose. Menthol produces a sensation of coolness and relieves minor throat irritation.