If your lips are ever dry, cracked, or perpetually peeling, chances are you’ve slabbed on a layer of Vaseline lip balm for quick relief. Petroleum jelly (aka petrolatum), its main ingredient, is the lip-care equivalent of a plain white tee: functional, unfussy, and relied upon for generations. But lately, chatter online has sparked questions about whether it actually does anything—or even causes harm. So are products that contain petroleum jelly actually good for your lips, or is this a habit we need to kick? Does petroleum jelly moisturize your lips? Some of petroleum jelly’s bad PR stems from the idea that it’s not technically a moisturizer to begin with. By definition, it’s actually an occlusive—meaning it creates a physical barrier to prevent moisture loss rather than actively adding hydration, says Jeremy Fenton, MD, board-certified dermatologist and medical director at Schweiger Dermatology in New York City and Long Beach, New York. Lips are notoriously bad at retaining moisture since they don’t have a thick layer of skin cells on the surface to protect them. That’s where …