Objective: Self-medication is promoted to extend healthy life expectancy. Accordingly, it is important for general consumers to properly use over-the-counter drugs. We investigated whether graphical symbols to visually aid the understanding of drug information (i.e., precautions and instructions to consult with a medical professional) provided in over-the-counter drug package inserts are easily understood in light of the International Organization for Standardization (ISO) criterion of 66％ comprehension. Methods: First, two questionnaire surveys were conducted with pharmacy students to calculate their comprehension level of the illustrations. The first round was for modifying illustrations that did not meet the ISO standard, and the second round was for seeing if comprehension had improved. Then, a questionnaire survey targeting general consumers was conducted to see if these illustrations functioned as graphical symbols. Results: When the referent of “Do not take this medicine if your experience falls under the following conditions” was placed in the upper left corner of the symbol, some students answered that this meant, “If you do not take this medicine, you will be under the following conditions,” but when it was placed in the lower right corner, many students accurately understood the intended information. In the student surveys, one illustration each for “cannot be taken/under treatment/heart,” “cannot be taken/under treatment/stomach,” “cannot be taken/under treatment/liver,” and “cannot be taken/under treatment/kidney” all exceeded 66％. Since none of the illustrations exceeded the 66％ comprehension in the survey of general consumers, it was found to be difficult for general consumers to understand drug information from the present illustrations. However, there were several illustrations that improved in comprehension compared to the previous study, which makes the continuation of this study significant. Conclusion: Although there were no illustrations exceeded 66％ comprehension of general consumers, the study shows that continued improvement may result in establishing pictograms for general consumers.