In recent years, the use of online courses has emerged as a way to quickly and easily deliver content to large numbers of trainees. In writing these courses, pharmaceutical course developers often use traditional instructional design models and techniques to design course content for online learning. But is this truly enough? Interaction design principles and practices can also be incorporated to increase the quality of learning by improving learner comprehension and retention. Using pharmaceutical content and learners, this research investigated how interaction design impacts online learning by measuring the effect of applying different graphical user interfaces. The results were surprising, as the data showed no significant improvement in retention rates between graphical treatments. However, the incorporation of graphics did slightly improve overall course satisfaction.