Is Sharing Nail Polish Really That Gross?

We’re all for sharing. But, when it comes to beauty, sampling from our friends’ makeup bags can sometimes inspire bacterial cross contamination, pink eye, and other nasty infections. While a hygienic approach to makeup may require closely guarded mascara wands, we wondered about the rules for sharing nail polish. Could that also put us at risk for passing infections?

Awhile back, we alerted you guys to a nail-polish rental service, which we thought was kind of neat. Then the comments section in the article exploded with people being horrified by this "gross" practice of nail-polish sharing. We had never thought of nail polish as being breeding ground for bacteria (too many chemicals, right?), but it did get us thinking, so we checked in with Dr. Chris Adigun, clinical assistant professor of dermatology at the New York University Langone Medical Center and dermatologist who specializes in nail disorders, for the final word.

“In general, sharing nail polish does not present a health or infection risk,” she says. “This is because the solvents in nail polish are chemically toxic to microorganisms by degrading their cell walls within seconds of contact. In fact, there have been studies that show that microbes cannot survive in nail lacquer, whether they are in a salon or deliberately contaminated with microorganisms for laboratory studies.” So, you don't have to give that much-used bottle of Mademoiselle at your local nail joint the stink-eye anymore.

And while natural, unpolished nails might seem like the most healthy choice when it comes to bacteria and infection risk, according to Adigun, the painted nail likely carries less bacteria. Wait, what? “Freshly polished nails have the added antimicrobial benefit of the solvents in the polish and actually have shown to have fewer colonized microbes than unpolished nails,” she says.

The trick to keeping nails in an antimicrobial state? Keep your paint job fresh, as chipped polish can harbor more bacteria, according to Adigun. While bacteria alone won’t likely pose much of a health risk, when paired with pushing or cutting of the cuticles, the chance of infection is raised.

Finally, in addition to keeping nails freshly painted, it also helps to keep the polish itself in microbial-fighting shape. “Make sure that the nail polish is securely closed after use, because solvents evaporate quickly and they are important for ensuring microorganisms do not survive,” Adigun says. If a polish is left open, add a few drops of acetone (an antimicrobial solvent). This will restore the polish’s natural consistency (as unsealed polishes tend to thicken) and kill any microorganisms that may have developed.

In short, keep those nail-painting sessions with your girls going — sharing polish won’t just inspire bright and shiny fingertips, but can help keep a bestie’s nails free of bacteria as well.