Twenty-five percent of people who borrow prescription medications experience side effects, according to new research.

The study, which was presented at the American Public Health Association’s 137th Annual Meeting & Exposition in Philadelphia, looked at whether prescription medication sharing, a common consumer health behavior, leads to adverse outcomes, including inappropriate usage, delayed care and exposure to side effects, says an APHA press statement.

Along with confirming previous results regarding prevalence of medication sharing, this study provides a first look at several consequences of prescription medication sharing. First, a large proportion of the study participants who admitted borrowing prescription medications reported never receiving written (54.6 percent) or verbal (38.2 percent) warnings or instructions from the person loaning the medicine.

Second, although 77.3 percent of participants who borrowed medication reported doing so rather than visiting their health care provider, almost 1 in 3 of those people ended up going to a health care provider nonetheless, thereby delaying care. Moreover, among those who delayed care, half reported that they failed to tell the provider about the use of borrowed prescription medication.

Additionally, 25.1 percent of prescription borrowers indicated that they had experienced a side effect when borrowing prescription medication.

“The results provide evidence that prescription medication borrowing presents real risks. Borrowers are frequently bypassing instructions and warnings, are avoiding or delaying seeking care from health professionals, are not communicating their borrowing to their health care provider, and are experiencing allergic reactions or side effects when they borrow prescription medications,” said Richard Goldsworthy, MSEd, Ph.D., lead researcher on the study.