Prozac is a selective serotonin reuptake inhibitor (SSRI) used to treat depression, obsessive-compulsive disorder (OCD), or bulimia. This medicine may also be used to treat PMS (premenstrual syndrome). It may also be used to treat other conditions as determined by your doctor.

Prozac was the first of a new class of drugs, called selective serotonin reuptake inhibitors (SSRIs), to be approved for use in the United States. This new type of medication helps patients with depression by increasing the availability of serotonin in the brain. Scientists believe serotonin affects many types of activity in the brain, including the regulation of mood.