Periactin, also known as cyproheptadine, is an antihistamine medication used for treatment of allergies, hay fever, and cold symptoms. It is also prescribed to stimulate appetite and promote weight gain in patients with anorexia or cachexia. Some common synonyms for periactin include cypriol, periact, ciprovit, and cyclivit. Other brand names for the medication include Cyproheptadine, Dynamogen, Periactine, and Tritogen. It is important to note that while there may be different names for the same medication, it is crucial to speak with a healthcare provider regarding all medication use and to follow dosage instructions carefully.