Cyproheptadine hydrochloride is a serotonin antagonist and a histamine H1 blocker used as antipruritic, appetite stimulant, antiallergic, and for the post-gastrectomy dumping syndrome, etc.

Cyproheptadine is an antihistamine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, sneezing, hives, and itching. It works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. This medication also blocks another natural substance in your body (serotonin).

Cyproheptadine is used in cats as an appetite a and as an adjunct in the treatment of asthma. Possible adverse effects include excitement and aggressive behavior. The elimination half-life of cyproheptadine in cats is 12 hours.

Cyproheptadine is a second line treatment for pituitary pars intermedia dysfunction in horses.