Cetcip L is a powerful medicine that works to control allergic symptoms caused by different types of allergens. The active ingredient in this pill is Levocitrizine, which falls in the category of drugs, such as antihistamines. There are various other generic versions of Levocitrizine that are available OTC also. The Cetcip L is an antihistamine drug. It works by reversibly blocking the production of histamine at a cellular level. It is a messenger chemical that is produced by immune cells to stimulate more immune cells. It works well to control symptoms like sneezing, runny nose, and red, watery, and itchy eyes.