The study identified whether there was a difference in responses toward a prescription drug ad based on endorser type. The study accessed allergy patients through an allergy clinic. About 204 patients took part in the study. Each of these patients was randomly assigned to one of the endorser groups (expert, typical consumer, and celebrity group) or to the control group. The study used four fictitious ads that featured the same fictitious allergy prescription medication. The ads looked the same except for the type of endorser. After evaluating one of the ads, the patients took a quick survey. The survey evaluated the patient's attitude toward the ad, the patient's attitude toward the drug in the ad, the patient's likelihood of asking the doctor for more information about the drug in the ad, and the patient's likelihood of asking the doctor to prescribe the drug in the ad. Findings revealed no significance differences in responses toward the prescription allergy medication print ad based on endorser type and therefore did not confirm the theory of endorser effectiveness. This was the first study to compare and contrast the use of different types of endorsers in direct to consumer advertisements (DTCAs) of prescription drugs. Future research could use these findings and test this study further by administering the survey to allergy patient in a non-clinical setting, by using different types of patients (those that have allergies, and those that do not), by using the television medium when evaluating responses based on endorser type, and by using different classes of medications when evaluating responses based on endorser type.