By Rifan Muazin 
To address the effectiveness of petroleum jelly, it is essential to first understand the unique anatomy of the lips. Unlike the skin on the rest of your body, the skin on your lips is incredibly thin, consisting of only three to five cellular layers compared to the sixteen layers found on typical facial skin. Furthermore, lips lack sebaceous glands, which produce the natural oils (sebum) that keep skin hydrated and protected. They also lack sweat glands and a significant concentration of melanin, leaving them vulnerable to both dehydration and UV damage. Because they have no built-in moisture-generating system, lips are exceptionally prone to transepidermal water loss (TEWL)—a process where water evaporates from the skin into the surrounding atmosphere.
This is where the debate over petroleum jelly begins. Much of the "bad PR" surrounding the product stems from a misunderstanding of what a moisturizer actually is. According to Jeremy Fenton, MD, a board-certified dermatologist and medical director at Schweiger Dermatology in New York City and Long Beach, petroleum jelly is not technically a moisturizer in the sense that it adds water to the skin. Instead, it is classified as an "occlusive." By definition, an occlusive creates a physical, hydrophobic barrier on the surface of the skin. This barrier acts like a plastic wrap, preventing existing moisture from escaping. "It helps to moisturize in that it allows the skin to retain and replenish its own moisture without battling against the constant transepidermal water loss that occurs without an occlusive," Dr. Fenton explains. While it doesn’t inject new hydration into the tissue, it is the most effective ingredient known to dermatology for stopping the evaporation of the hydration that is already there.
Beyond its occlusive properties, petrolatum also functions as an emollient. Ava Shamban, MD, a board-certified dermatologist and founder of AVA MD in Santa Monica and Beverly Hills, notes that emollient properties are what give the product its ability to smooth and soften the skin. When lips are dry and peeling, the skin cells (corneocytes) become jagged and lifted. Emollients fill the gaps between these cells, resulting in a smoother texture and providing immediate relief from the physical discomfort of cracking. Therefore, the bottom line on efficacy is nuanced: petrolatum is a master at sealing and softening, but if your lips are already bone-dry and "empty" of moisture, applying an occlusive alone might feel like sealing an empty well.
The second major pillar of the petroleum jelly controversy is safety. Because petrolatum is derived from the refining of crude oil—the same source used for gasoline and motor oil—critics often label it as toxic or potentially carcinogenic. This assumption, while understandable on the surface, ignores the rigorous purification processes required for cosmetic-grade products. Dr. Shamban emphasizes that products sold by reputable, major brands like Vaseline or Aquaphor have been highly processed and refined to remove polycyclic aromatic hydrocarbons (PAHs), which are the impurities that would be toxic or unhealthy. In fact, the "White Petrolatum" found in these tubs meets United States Pharmacopeia (USP) standards, meaning it is pure enough for use in food and medical settings.
Dermatologists frequently point to the long history of petroleum jelly in clinical environments as proof of its safety. It is a hypoallergenic substance, making it a gold standard for wound care in hospitals because it rarely causes allergic reactions—a claim many "natural" plant-based balms cannot make. Dr. Fenton adds that petroleum jelly is a large-molecule substance that cannot penetrate deeper than the very top layer of the skin. This means it is not absorbed systemically into the bloodstream, posing virtually no risk of internal toxicity. Both experts agree that while the "petroleum" name may sound unappealing in a world focused on botanical ingredients, refined petrolatum carries virtually no risk of carcinogenicity when sourced from reputable manufacturers.
Despite the internet’s attempts to "cancel" the ingredient, many top dermatologists remain its fiercest defenders. David Kim, MD, board-certified dermatologist and founder of Soho Dermatology in New York City, is blunt in his assessment: "Vaseline Lip Therapy is the best lip balm, period. There is nothing else that works nearly as well to moisturize the lips." For Dr. Kim, the simplicity of the formula is its strength. In a market flooded with complex peptides and exotic oils, a single-ingredient occlusive provides a reliable shield that allows the lip’s natural healing processes to take place undisturbed by environmental irritants.
However, for those dealing with chronic, severe dryness, the "sandwich" method of application is often recommended. Since petroleum jelly doesn’t add moisture, Drs. Fenton and Shamban suggest a two-step approach. First, apply a humectant—an ingredient that draws water into the skin. Common humectants include hyaluronic acid, glycerin, or polyglutamic acid (PGA). Applying a humectant-rich serum or a damp cloth to the lips introduces a surge of hydration. Following this immediately with a layer of petroleum jelly "locks" that water in, providing a level of hydration that neither product could achieve alone.
While petrolatum is the heavyweight champion of occlusives, it is not the only option available for those seeking a more complex lip care routine. Ingredients like beeswax provide a different textural experience. Beeswax is stickier and has a higher melting point than petroleum jelly, which Dr. Fenton notes helps it stay on the lips longer, reducing the need for constant reapplication. Shea butter is another favorite among dermatologists for its high fatty acid content, which provides intense emollient benefits. These ingredients are often combined in high-performance products like Aquaphor’s Lip Repair, which is frequently cited by experts as a top-tier choice because it balances the occlusive power of petrolatum with the healing properties of shea butter and vitamins.
For those interested in the cutting edge of skin barrier repair, ceramides are becoming a staple in lip care. Ceramides are lipids naturally found in the skin barrier that help hold cells together. Dr. Kim highlights their importance in strengthening the delicate lip tissue against external stressors. Products like Allies of Skin Peptide and Ceramide Repair Lip Balm or Dr. Jart+ Ceramidin Lip Balm utilize these lipids alongside hydrating glycerin and soothing panthenol to rebuild the barrier rather than just covering it. Furthermore, for those who prefer an ingredient that can actually penetrate the skin’s outer layer, Dr. Shamban points to lanolin. Lanolin, a wax secreted by wool-bearing animals, is a unique "triple threat" that acts as an emollient, occlusive, and humectant. It can mimic human skin lipids, allowing it to both hold moisture within the tissue and seal it from the outside. However, users should be cautious, as lanolin is a known allergen for a small percentage of the population.
In the quest for healthy lips, knowing what to avoid is just as critical as knowing what to apply. Many popular lip balms contain "medicated" ingredients like menthol, camphor, or phenol. While these provide a cooling sensation that feels like it’s "working," they are actually counterproductive. These ingredients are counter-irritants that can cause the top layers of skin to peel off, leaving the lips even more vulnerable and creating a "cycle of addiction" where the user feels they need more balm to soothe the irritation caused by the balm itself. Dr. Shamban also advises against flavored balms, alcohols, and heavy fragrances, which are leading causes of allergic contact dermatitis on the lips. Even the recent trend of using beef tallow in lip care is met with skepticism from the medical community. "There’s nothing to see here," says Dr. Shamban, suggesting that such "fringe" ingredients often lack the refinement and safety data of established skincare staples.
Ultimately, the controversy surrounding petroleum jelly appears to be a classic case of modern marketing clashing with old-school science. While the source material may be unglamorous, the refined end product remains one of the most effective, safest, and most affordable tools in a dermatologist’s arsenal. It provides a necessary shield for a part of the body that has no natural defense against the elements. Whether you choose a classic tub of Vaseline, a specialized SPF-infused balm like Jack Black’s Intense Therapy, or a high-end ceramide treatment, the goal remains the same: stop the loss of water and give the skin the peace it needs to repair itself. For the vast majority of people, petroleum jelly isn’t a habit to kick—it’s a foundational step in maintaining a healthy skin barrier.