The situation: Your favorite lip balm only comes in one of those little tubs or ramekins—not a stick-style applicator. You know it’s a good idea to wash your fingers before digging them in there and balming up. But you’re usually out and about when your mouth cries out for moisture or sun protection.
What you’re worried about: Bacteria, viruses, and all the other invisible sickness-causing microorganisms that could be living on your finger or festering in the petri dish you still think of as lip balm. “Even if there’s an antigen in the balm that’s meant to prevent bacterial growth, that won’t protect you if you have bacteria on your fingers when you apply the balm,” says Elaine Larson, PhD, an infectious disease researcher and professor at Columbia University. Just seeing a dude with a cold sore leaves you wondering if his oral herpes creepy crawlies have snuck into you balm’s canister.
The very worst thing that could happen: After touching a doorknob or railing—or your cell phone—your finger could pick up streptococcus (strep) or staphylococcus (staph) bacteria, says Adam Friedman, MD, a dermatologist at George Washington University. While staph bacteria can cause pneumonia, some species of strep can infect you with strep throat, pink eye, meningitis, and even “flesh-eating disease.” (Do NOT, we repeat, do NOT, Google that.)
What will probably happen: Sooner or later—especially if you keep your lip balm in your purse, which may be filthier than a public toilet—you’re probably going to contract a run-of-the-mill cold or stomach bug, Friedman says. “It will help if you wash your hands really well before using the balm,” he explains. “But avoiding some kind of infection is really a matter of time and luck.”
Larson adds: “Just thinking about this logically, it’s not a good idea to keep sticking your finger in something and then touching your mouth.”
Experts used to think illness-causing bacteria died quickly when deposited on public surfaces. But a 2013 study in Infection and Immunity found germs can survive outside a living host for weeks or even months. Friedman says some of the ingredients in lip balm provide an ideal environment for bacteria to thrive. So the longer you keep your balm, the more likely it is to pick up something nasty.
Bottom-line: It’s probably time to switch to a stick-style lip balm.