In one-on-one interviews with 700 Americans, roughly 23 percent reported loaning their prescription medications to someone else, and 27 percent reported borrowing prescription medications.

According to Reuters Health, the medications most frequently shared, loaned or borrowed were allergy drugs like Allegra (25 percent), followed by pain medications like Darvoset and OxyContin (22 percent); and antibiotics like amoxicillin (21 percent).

Seven percent of the people interviewed said they shared mood-altering drugs like Paxil, Zoloft, Ritalin and Valium, with a little more than 6 percent admitting they shared the prescription anti-acne drug Accutane. About 5 percent shared birth control pills, the study said.

The findings aren’t surprising, but the extent of sharing was higher than the researchers expected, Reuters said.

The study was led by Dr. Richard Goldsworthy, Director of Research & Development at The Academic Edge, Inc. Bloomington, Indiana, and will appear in the American Journal of Public Health.

“While ideally people should never share any medications, realistically, people do in fact share them and in many cases, such as allergy medicine, doing so is beneficial and carries little risk,” Goldsworthy said.

On the other hand, sharing prescription medicine can be associated with significant risks, especially with antibiotics, since a full course of treatment is supposed to be completed when you use them, he added.

Goldsworthy also warned that certain classes of drugs are “teratogenic”—meaning they cause birth defects, sometimes even if taken a month before conception. Those drugs, which include the anti-acne drug Accutane should never be shared.

“For pain relievers, allergy medicines, and other symptom-alleviating medications, if you are going to give someone a prescription medicine, you should be mindful to provide them with any instructions and warnings. Similarly, if you borrow one, you should worry about how to take it and when not to do so,” Goldsworthy suggested. “If you borrow prescription medicine, tell your tell your doctor about it.”

The survey showed that Whites and Hispanics were more apt to share prescription pain medicines than were African Americans, and women were more apt than men to share antibiotics.

People seemed most willing to share prescription medicine when the medication came from a family member, they had a prescription for a particular medication but ran out of it or did not have it with them, or they had an emergency, Reuters said.