Prozac is an antidepressant drug marketed by Eli Lilly and Company. The drug is commonly prescribed to patients who suffer from depression, obsession compulsive disorder (OCD), anxiety, and other mental illnesses. It may also be used to treat other medical conditions which are not related to depression or mental illnesses. Prozac has been linked to serious side effects including causing birth defects. Before taking Prozac consult with an experienced medical professional.