Nonprescription medications are relatively safe, but not risk-free and can lead to serious adverse events, particularly if used contrary to directions or without attention to depicted warnings. The question arises whether the information presented on the product label is readable and comprehensible to the average lay person. We examined the product labels of nonprescription medications for readability and comprehensibility characteristics using the Flesch-Kincaid method. The Flesch-Kincaid reading ease scores and grade level scores were derived. We further validated the grade level scores using the Gunning-Fog method. Qualitative assessment of select labels found severe deficiencies such as poor organization and inundation with technical terms. By quantitative assessment the average reading ease score of 40 nonprescription medication labels (including nonsteroidal anti-inflammatory agents, antacids, laxative preparations, anti-allergy medications, H-2 blockers, proton pump inhibitors, sleep aids, an antiasthmatic, and cough and cold remedies) was 38 ± 12. The average Flesch-Kincaid grade level score was 16 ± 5. All labels except one were at reading grade level greater than the eighth grade. The average grade level of education necessary to understand the material according to the Gunning-Fog method was 17 ± 5 and all labels were above the eighth grade reading level. Nonprescription medication labels are written in a language that is not comprehensible to the average member of the general public. There is a need for considerable improvement in the readability of these labels.