The brand names all roll off the tips of our tongues … Tylenol, Motrin, Bayer Aspirin, Advil and more. All offer some sort of relief from headaches, pain or fever, yet each contains different ingredients that for some may cause allergic reactions, side effects or dangerous drug interactions.

These over-the-counter medications are consumed each year by the billions. And yet research shows that many people have no idea what specific ingredient is contained in each product.

A new study in the American Journal of Preventive Medicine involved testing forty-five adults on their familiarity and use of over-the-counter painkillers. Almost half of the subjects read at, or below, a sixth-grade level. People with limited education and low incomes tend to be most vulnerable to medication safety issues.

Analysis of the data showed that a good three-fourths of the participants did know that aspirin was the main ingredient in the Bayer product. But less than half knew that Motrin contains ibuprofen, only one-third knew that Tylenol contains acetaminophen, and less than one-fifth knew the active ingredients in either Aleve or Advil. In addition, findings indicated that only forty percent of those tested even read the ingredient label on any medication. Researchers say these results are not overly surprising, though. Past studies have shown that parents of young children are also often confused about labels on liquid over-the-counter medications.

The scientists note that labels often contain wording that is confusing, which creates the potential for several dangerous scenarios.

To address the confusion, the researchers suggest that universal icons associated with specific ingredients be placed on all corresponding medications. Also, making warnings about reactions and interactions more simple and clear could help, too.