Prozac^® (fluoxetine hydrochloride) is a medication that is approved to treat depression, panic disorder, obsessive-compulsive disorder (OCD), and bulimia. This prescription medication is a type of selective serotonin reuptake inhibitor (SSRI); it works by allowing a certain chemical (serotonin) to stay in the brain for a longer period of time. Prozac comes in the form of a capsule or a liquid, and is typically taken once or twice a day. A few of the common side effects seen with Prozac include diarrhea, headaches, and a loss of appetite.